* Check if file is locked on upload file commit.

* Better user message if file is locked.

* Check lfs lock before creating temporary repository. fix some errors.

* move lines

* Add comment that enabled setting is checked.

Replaces #8182

* update #8687 respect file locking

* upate #8687 Add LFS locker information

* update #8719 enhance coding style and return error

This PR adds basic repository LFS management UI including the ability to find all possible pointers within the repository. Locks are not managed at present but would be addable through some simple additions.

* Add basic repository lfs management
* add auto-associate function
* Add functionality to find commits with this lfs file
* Add link to find commits on the lfs file view
* Adjust commit view to state the likely branch causing the commit
* Only read Oid from database

* Send email to assigned user

* Only send mail if enabled

* Mail also when assigned through API

* Need to refactor functions from models to issue service

* Refer to issue index rather than ID

* Disable email notifications completly at initalization if global disable

* Check of user enbled mail shall be in mail notification function only

* Initialize notifications from routers init function.

* Use the assigned comment when sending assigned mail

* Refactor so that assignees always added as separate step when new issue/pr.

* Check error from AddAssignees

* Check if user can be assiged to issue or pull request

* Missing return

* Refactor of CanBeAssigned check.

CanBeAssigned shall have same check as UI.

* Clarify function names (toggle rather than update/change), and clean up.

* Fix review comments.

* Flash error if assignees was not added when creating issue/pr

* Generate error if assignee users doesn't exist

Fix #8461 - fix misspelling of {{AppSubUrl}} and other misspelling in template
Fixes /explore and organisation redirection

Add 'Alt + click' and 'Alt +enter' feature to exclude particular labels on searching for issues.

Add an option to protected branches to add writing deploy keys to the whitelist for pushing.

Please note this is technically a breaking change: previously if the owner of a repository was on the whitelist then any writing deploy key was effectively on the whitelist. This option will now need to be set if that is desired.

Closes #8472 

Details:
* Allow Protected Branches to Whitelist Deploy Keys
* Add migration
* Ensure that IsDeployKey is set to false on the http pushes
* add not null default false

* Allow committing / adding empty files from the web ui (#8420)

Signed-off-by: LukBukkit <luk.bukkit@gmail.com>

* Add a modal to confirm the commit of an empty file

Signed-off-by: LukBukkit <luk.bukkit@gmail.com>

This PR fixes #7598 by providing a configurable way of signing commits across the Gitea instance. Per repository configurability and import/generation of trusted secure keys is not provided by this PR - from a security PoV that's probably impossible to do properly. Similarly web-signing, that is asking the user to sign something, is not implemented - this could be done at a later stage however.

## Features
- [x] If commit.gpgsign is set in .gitconfig sign commits and files created through repofiles. (merges should already have been signed.)
- [x] Verify commits signed with the default gpg as valid
- [x] Signer, Committer and Author can all be different
    - [x] Allow signer to be arbitrarily different - We still require the key to have an activated email on Gitea. A more complete implementation would be to use a keyserver and mark external-or-unactivated with an "unknown" trust level icon.
- [x] Add a signing-key.gpg endpoint to get the default gpg pub key if available
    - Rather than add a fake web-flow user I've added this as an endpoint on /api/v1/signing-key.gpg
    - [x] Try to match the default key with a user on gitea - this is done at verification time
- [x] Make things configurable?
    - app.ini configuration done
    - [x] when checking commits are signed need to check if they're actually verifiable too
- [x] Add documentation

I have decided that adjusting the docker to create a default gpg key is not the correct thing to do and therefore have not implemented this.