Added SocketApplicationCommands, Added method in SocketGuild to fetch that guilds ApplicationCommands.

Tested all rest routes and fixed them accordingly.

Did more testing and I think its ready to go

New Rest entities: RestApplicationCommand,RestGlobalCommand, RestGuildCommand, RestApplicationCommandOption, RestApplicationCommandChoice, RestApplicationCommandType.

Added public methods to the RestClient to fetch/create/edit interactions.

Signed-off-by: Still Hsu <dev@stillu.cc>

* Fix: HasAllMembers is false if a user left

* Fix: Correct boolean logic

* Update SocketGuild.cs

* Fix returns value docs

Signed-off-by: Still Hsu <dev@stillu.cc>

Co-authored-by: Still Hsu <dev@stillu.cc>

The inherited summary incorrectly stated that all users who _see_ the channel are returned when in reality only the ones _connected_ are.

* Add inline replies

* Missed a few things

* Change xml docs, IUserMessage, and other changes

* Missed one when changing

* Fix referencedMessage author

* Send presence on identify

* Change CurrentUser presence

* Implement gateway ratelimit

* Remove unused code

* Share WebSocketRequestQueue between clients

* Add global limit and a way to change gateway limits

* Refactoring variable to fit lib standards

* Update xml docs

* Update xml docs

* Move warning to remarks

* Remove specific RequestQueue for WebSocket and other changes

The only account limit is for identify that is dealt in a different way (exclusive semaphore), so websocket queues can be shared with REST and don't need to be shared between clients anymore.

Also added the ratelimit for presence updates.

* Add summary to IdentifySemaphoreName

* Fix spacing

* Add max_concurrency and other fixes

- Add session_start_limit to GetBotGatewayResponse
- Add GetBotGatewayAsync to IDiscordClient
- Add master/slave semaphores to enable concurrency
- Not store semaphore name as static
- Clone GatewayLimits when cloning the Config

* Add missing RequestQueue parameter and wrong nullable

* Add RequeueQueue paramater to Webhook

* Better xml documentation

* Remove GatewayLimits class and other changes

- Remove GatewayLimits
- Transfer a few properties to DiscordSocketConfig
- Remove unnecessary usings

* Remove unnecessary using and wording

* Remove more unnecessary usings

* Change named Semaphores to SemaphoreSlim

* Remove unused using

* Update branch

* Fix merge conflicts and update to new ratelimit

* Fixing merge, ignore limit for heartbeat, and dispose

* Missed one place and better xml docs.

* Wait identify before opening the connection

* Only request identify ticket when needed

* Move identify control to sharded client

* Better description for IdentifyMaxConcurrency

* Add lock to InvalidSession

* Add missing properties to Guild, related methods, and deprecate GuildEmbed endpoints

- Add missing guild properties: `discovery_splash`, `widget_enabled`, `widget_channel_id`, `rules_channel_id`, `max_presences`, `max_presences`, `max_members`, `public_updates_channel_id`, `max_video_channel_users`, `approximate_member_count`, `approximate_presence_count`
- Update guild properties: `embed_enabled`, `embed_channel_id`
- Add `GetGuildDiscoverySplashUrl` to `CDN`
- Add classes related to the guild widget
- Add `withCounts` parameter to `GetGuild(s)Async`
- Make GuildEmbed related methods obsolete with a message redirecting to widget ones

* Change xml docs and PremiumSubscriptionCount type

* Changed some xml docs