Add /api/v1/accounts/familiar_followers to REST API (#17700)

* Add `/api/v1/accounts/familiar_followers` to REST API

* Change hide network preference to be stored consistently for local and remote accounts

* Add dummy classes to migration

* Apply suggestions from code review

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

config/settings.yml

@@ -17,7 +17,6 @@ defaults: &defaults
   timeline_preview: true
   show_staff_badge: true
   default_sensitive: false
-  hide_network: false
   unfollow_modal: false
   boost_modal: false
   delete_modal: true