Also, AppContext, APIService, and AuthenticationServiceProvider are now more obviously singletons.
And AuthenticationServiceProvider can now be asked for the current active user, instead of every caller assuming the first element of a list of users is the active user.
* Add moderation-warning-notification-type (IOS-264)
* Add entity for new AccountWarning (IOS-264)
Details see https://github.com/mastodon/mastodon/pull/30065 for now, as there's no documentation (yet)
* re-add file header (IOS-264)
* Add authorization to instance-calls (IOS-264)
This will improve using the app with `LIMITED_FEDERATION_INSTANCES`
* Add basic cell for account-warnings (IOS-264)
* Show some content for a warning (IOS-264)
* Open strike in browser (IOS-264)
* Add localization (IOS-264)
* Add missing localization (IOS-264)
* Cleanup (IOS-264)
