Groups can enable/disable LFS, but this setting can be overridden at the project level. Admin only

There is a race condition in DestroyGroupService now that projects are deleted asynchronously:

1. User attempts to delete group
2. DestroyGroupService iterates through all projects and schedules a Sidekiq job to delete each Project
3. DestroyGroupService destroys the Group, leaving all its projects without a namespace
4. Projects::DestroyService runs later but the can?(current_user,
   :remove_project) is `false` because the user no longer has permission to
   destroy projects with no namespace.
5. This leaves the project in pending_delete state with no namespace/group.

Projects without a namespace or group also adds another problem: it's not possible to destroy the container
registry tags, since container_registry_path_with_namespace is the wrong value.

The fix is to destroy the group asynchronously and to run execute directly on Projects::DestroyService.

Closes #17893

And create new Project#requesters, Group#requesters scopes.

Signed-off-by: Rémy Coutable <remy@rymai.me>

# Conflicts:
#	app/models/issue.rb
#	app/views/projects/_home_panel.html.haml
#	app/views/shared/projects/_project.html.haml
#	db/schema.rb
#	spec/models/project_spec.rb