Remove duplicate attributes from discussion entity and move note.can_edit into note.current_user

app/serializers/discussion_entity.rb

@@ -3,18 +3,8 @@ class DiscussionEntity < Grape::Entity
 
   expose :id, :reply_id
   expose :expanded?, as: :expanded
-  expose :author, using: UserEntity
-
-  expose :created_at
-
-  expose :last_updated_at, if: -> (discussion, _) { discussion.updated? }
-  expose :last_updated_by, if: -> (discussion, _) { discussion.updated? }, using: UserEntity
 
   expose :notes, using: NoteEntity
 
   expose :individual_note?, as: :individual_note
-
-  expose :can_reply do |discussion|
-    can?(request.current_user, :create_note, discussion.project)
-  end
 end

app/serializers/note_entity.rb

@@ -17,9 +17,11 @@ class NoteEntity < API::Entities::Note
   expose :last_edited_at, if: -> (note, _) { note.is_edited? }
   expose :last_edited_by, using: UserEntity, if: -> (note, _) { note.is_edited? }
 
+  expose :current_user do
     expose :can_edit do |note|
       Ability.can_edit_note?(request.current_user, note)
     end
+  end
 
   expose :system_note_icon_name, if: -> (note, _) { note.system? } do |note|
     SystemNoteHelper.system_note_icon_name(note)