Added bookmarks

• Added:
- bookmarks for GabPRO members only
- migration for creation of StatusBookmarks
- all necessary routes, controllers
- redux for adding, removing, fetching and displaying bookmarks
- bookmark icon
- doorkeeper scopes
- backend and frontend support

Bookmarks behave like likes/favorites, except they aren't shared with other users and do not have an associated counter.

dfea7368c9

app/models/concerns/account_interactions.rb

@@ -189,6 +189,10 @@ module AccountInteractions
     status.proper.favourites.where(account: self).exists?
   end
 
+  def bookmarked?(status)
+    status_bookmarks.where(account: self).exists?
+  end
+
   def reblogged?(status)
     status.proper.reblogs.where(account: self).exists?
   end