API: remove various associated fields included by default.

Remove various associated fields that were included by default on
certain endpoints. API users can use the only param to include the
full association if they need these fields.

* /artists.json: urls.
* /artist_urls.json: artist.
* /comments.json: creator_name and updater_name.
* /notes.json: creator_name.
* /pools.json: creator_name.
* /posts.json: uploader_name, children_ids, pixiv_ugoira_frame_data.
* /post_appeals.json: is_resolved.
* /post_versions.json: updater_name.
* /uploads.json: uploader_name.

app/models/note.rb

@@ -11,8 +11,6 @@ class Note < ApplicationRecord
   after_save :create_version
   validate :post_must_not_be_note_locked
 
-  api_attributes including: [:creator_name]
-
   module SearchMethods
     def active
       where("is_active = TRUE")
@@ -28,10 +26,6 @@ class Note < ApplicationRecord
     end
   end
 
-  def creator_name
-    creator.name
-  end
-
   extend SearchMethods
 
   def post_must_not_be_note_locked