Change ActivityPub paging to match spec. Clean up ActivityPub outbox changes. (#2410)

* Change ActivityPub paging to match spec. Clean up ActivityPub outbox changes.

* Fix code style and test failures for OutboxController.

* Attempt to fix CI errors.

app/controllers/api/activitypub/notes_controller.rb

@@ -6,8 +6,6 @@ class Api::Activitypub::NotesController < ApiController
   respond_to :activitystreams2
 
   def show
-    headers['Access-Control-Allow-Origin'] = '*'
-
     forbidden unless @status.permitted?
   end