* Add silent column to mentions

* Save silent mentions in ActivityPub Create handler and optimize it

Move networking calls out of the database transaction

* Add "limited" visibility level masked as "private" in the API

Unlike DMs, limited statuses are pushed into home feeds. The access
control rules between direct and limited statuses is almost the same,
except for counter and conversation logic

* Ensure silent column is non-null, add spec

* Ensure filters don't check silent mentions for blocks/mutes

As those are "this person is also allowed to see" rather than "this
person is involved", therefore does not warrant filtering

* Clean up code

* Use Status#active_mentions to limit returned mentions

* Fix code style issues

* Use Status#active_mentions in Notification

And remove stream_entry eager-loading from Notification

* Remove most behaviour disparities between blocks and mutes

The only differences between block and mute should be:

- Mutes can optionally NOT affect notifications
- Mutes should not be visible to the muted

Fix #7230
Fix #5713

* Do not allow boosting someone you blocked

Fix #7248

* Do not allow favouriting someone you blocked

* Fix nil error in StatusPolicy

* Adjust policy to allow boosting own private toots

* Add ability to reblog private toots from dropdown menu

* Add moderator role and add pundit policies for admin actions

* Add rake task for turning user into mod and revoking it again

* Fix handling of unauthorized exception

* Deliver new report e-mails to staff, not just admins

* Add promote/demote to admin UI, hide some actions conditionally

* Fix unused i18n

* Add status destroy authorization to policy

* Create explicit unreblog status authorization