users: replace scopes with associations.

app/models/note.rb

@@ -20,14 +20,6 @@ class Note < ApplicationRecord
       where(post_id: PostQueryBuilder.new(query).build.reorder(""))
     end
 
-    def for_creator(user_id)
-      where("creator_id = ?", user_id)
-    end
-
-    def creator_name(name)
-      where("creator_id = (select _.id from users _ where lower(_.name) = ?)", name.mb_chars.downcase)
-    end
-
     def search(params)
       q = super