* Feature: Allowed mentions object on msg create (interface breaking)

This change implements the AllowedMentions object for the payload of message creation. By default, the mentions behavior remains unchanged, the message content is parsed for all mentionable entities and they are all notified. If this payload is not null, it will use the content of the allowed_mentions field to determine if a role is notified, or just displayed.

This change is interface breaking. This follows the conventions of keeping RequestOptions as the last argument, but could break some users who specify each of these arguments without using named arguments.

* lint: remove commented-out code

This change removes the commented-out code which was added during testing from the previous commit.

* fix interface break: reorder allowedMentions arg so that it's after options

This change modifies the order of the AllowedMentions argument of SendMessageAsync so that this addition shouldn't be interface breaking. The downside to this change is that it breaks the convention followed by other methods, where the RequestOptions argument is normally last.

* docs: fix typo in allowedMentions arg doc

* fix interface break arg from IRestMessageChannel

* docs: update xmldoc for allowedMentions args

* fix interface breaking arg order for ISocketMessageChannel

* fix mocked classes that weren't updated

* fix: RestDMChannel#SendMessageAsync bug, allowed mentions always null

This change fixes a bug that was introduced while testing changes to the interface of the SendMessageAsync method to try and retain interface compatibility

* docs: update xmldoc for AllowedMentions type

* docs: reword xmldoc of AllowedMentionTypes type

* docs: fix typo

* fix: validate that User/Role flags and UserIds/RoleIds lists are mutually exclusive

This change adds validation to SendMessageAsync which checks that the User flag is mutually exclusive with the list of UserIds, and that the Role flag is also mutually exclusive with the list of RoleIds

* docs: reword summaries for AllowedMentions type

* Add util properties for specifying all or no mentions

Adds read only properties which specify that all mentions or no mentions will notify users. These settings might be more common than others, so this would make them easier to use.

* docs: Resolve PR comments for documentation issues/typos

* Update all dependencies and deal with warning/errors

* Add updated AsyncEnumerable implementation

* Fix broken target

* Cleanup

* Remove obsolete message

* typo

* Update azure pipelines

* Update samples to .NET Core 3.0

* Pull out test change

* Install the .net core 3 SDK on the ubuntu image for the time being

* Target net core 3 for the unit tests because pipelines

* Squashed commit of test rewrite changes

fix missing priority speaker flag

rewrite the TestChannelPermissionModify test

add test for GuildPermission modify

separate unit and integration tests, start writing channel and guild permission tests

copy over the color tests

copy over the emote tests

copy the token utils tests

make the mocked entities sealed classes

copy the TypeReaderTests class

properly dispose the CommandService in the TypeReaderTests

start writing tests for EmbedBuilder and related classes

test that properties throw ArgumentException when invalid

add tests for the embed length property

add withFooter tests

finish adding tests to EmbedBuilder

fix bug in value validation of EmbedFieldBuilder

hey, these tests actually found a bug!

add tests for the MentionUtils class

add tests for the Format util class

remove all of the old tests

add analyzer tests (copied from old tests)

add tests for the SnowflakeUtils class

add integration tests

these get around the issue of state persisting between tests by creating and deleting a guild for each set of tests. these shouldn't be run excessively because of the rate limits, but should be fine every now and then

remove unnecessary launchSettings.json

update outdated string

don't create a new guild each time, as that can result in errors

this can happen if a bot creates too many guilds without properly deleting them

add some tests that show that guild can be modified

await async assert

add more measures that created channels are deleted when done

remove "Test" prefix from test method names

I think that this prefix when already displayed under a class with a suffix of "Tests" is redundant

Remove mention of old test project

fix an issue from forgetting to await Assert.ThrowsAsync

explicitly disable parallelization on integration tests

add test for GuildPermission modify

separate unit and integration tests, start writing channel and guild permission tests

copy over the color tests

copy over the emote tests

make the mocked entities sealed classes

properly dispose the CommandService in the TypeReaderTests

fix bug in value validation of EmbedFieldBuilder

hey, these tests actually found a bug!

add tests for the MentionUtils class

add tests for the Format util class

remove all of the old tests

add analyzer tests (copied from old tests)

add tests for the SnowflakeUtils class

add integration tests

these get around the issue of state persisting between tests by creating and deleting a guild for each set of tests. these shouldn't be run excessively because of the rate limits, but should be fine every now and then

remove unnecessary launchSettings.json

update outdated string

don't create a new guild each time, as that can result in errors

this can happen if a bot creates too many guilds without properly deleting them

add more measures that created channels are deleted when done

remove "Test" prefix from test method names

I think that this prefix when already displayed under a class with a suffix of "Tests" is redundant

Remove mention of old test project

fix an issue from forgetting to await Assert.ThrowsAsync

explicitly disable parallelization on integration tests

update the azure CI build script

separate execution of test projects so that if one fails the other will not pass

one of the unit tests failed, but the analzyer tests passed

fix test that would break in different timezones

enable the integration tests (only on dev branch)

* Squashed commit of test rewrite changes

fix missing priority speaker flag

rewrite the TestChannelPermissionModify test

add test for GuildPermission modify

separate unit and integration tests, start writing channel and guild permission tests

copy over the color tests

copy over the emote tests

copy the token utils tests

make the mocked entities sealed classes

copy the TypeReaderTests class

properly dispose the CommandService in the TypeReaderTests

start writing tests for EmbedBuilder and related classes

test that properties throw ArgumentException when invalid

add tests for the embed length property

add withFooter tests

finish adding tests to EmbedBuilder

fix bug in value validation of EmbedFieldBuilder

hey, these tests actually found a bug!

add tests for the MentionUtils class

add tests for the Format util class

remove all of the old tests

add analyzer tests (copied from old tests)

add tests for the SnowflakeUtils class

add integration tests

these get around the issue of state persisting between tests by creating and deleting a guild for each set of tests. these shouldn't be run excessively because of the rate limits, but should be fine every now and then

remove unnecessary launchSettings.json

update outdated string

don't create a new guild each time, as that can result in errors

this can happen if a bot creates too many guilds without properly deleting them

add some tests that show that guild can be modified

await async assert

add more measures that created channels are deleted when done

remove "Test" prefix from test method names

I think that this prefix when already displayed under a class with a suffix of "Tests" is redundant

Remove mention of old test project

fix an issue from forgetting to await Assert.ThrowsAsync

explicitly disable parallelization on integration tests

add test for GuildPermission modify

separate unit and integration tests, start writing channel and guild permission tests

copy over the color tests

copy over the emote tests

make the mocked entities sealed classes

properly dispose the CommandService in the TypeReaderTests

fix bug in value validation of EmbedFieldBuilder

hey, these tests actually found a bug!

add tests for the MentionUtils class

add tests for the Format util class

remove all of the old tests

add analyzer tests (copied from old tests)

add tests for the SnowflakeUtils class

add integration tests

these get around the issue of state persisting between tests by creating and deleting a guild for each set of tests. these shouldn't be run excessively because of the rate limits, but should be fine every now and then

remove unnecessary launchSettings.json

update outdated string

don't create a new guild each time, as that can result in errors

this can happen if a bot creates too many guilds without properly deleting them

add more measures that created channels are deleted when done

remove "Test" prefix from test method names

I think that this prefix when already displayed under a class with a suffix of "Tests" is redundant

Remove mention of old test project

fix an issue from forgetting to await Assert.ThrowsAsync

explicitly disable parallelization on integration tests

update the azure CI build script

separate execution of test projects so that if one fails the other will not pass

one of the unit tests failed, but the analzyer tests passed

fix test that would break in different timezones

enable the integration tests (only on dev branch)

* Update mocked channels for changed SendFileAsync signature

* comment out the integration tests from the build script

no bot token is provided to this script, and use of integration tests in CI is questionable here

* force rebuild because Azure linux build broke