Add notifications when a reblogged status has been updated (#17404)

* Add notifications when a reblogged status has been updated

* Change wording to say "edit" instead of "update" and add missing controls

* Replace previous update notifications with the most up-to-date one

app/serializers/rest/notification_serializer.rb

@@ -11,6 +11,6 @@ class REST::NotificationSerializer < ActiveModel::Serializer
   end
 
   def status_type?
-    [:favourite, :reblog, :status, :mention, :poll].include?(object.type)
+    [:favourite, :reblog, :status, :mention, :poll, :update].include?(object.type)
   end
 end