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/post_archive.rb

@@ -266,12 +266,8 @@ class PostArchive < ApplicationRecord
     post&.visible? && user.is_member?
   end
 
-  def updater_name
-    updater&.name
-  end
-
   def api_attributes
-    super + [:obsolete_added_tags, :obsolete_removed_tags, :unchanged_tags, :updater_name]
+    super + [:obsolete_added_tags, :obsolete_removed_tags, :unchanged_tags]
   end
 
   def self.available_includes