FEATURE: New 'Reviewable' model to make reviewable items generic

Includes support for flags, reviewable users and queued posts, with REST API
backwards compatibility.

Co-Authored-By: romanrizzi <romanalejandro@gmail.com>
Co-Authored-By: jjaffeux <j.jaffeux@gmail.com>

script/import_scripts/nodebb/nodebb.rb

@@ -410,11 +410,7 @@ class ImportScripts::NodeBB < ImportScripts::Base
             post["upvoted_by"].each do |upvoter_id|
               user = User.new
               user.id = user_id_from_imported_user_id(upvoter_id) || Discourse::SYSTEM_USER_ID
-
-              begin
-                PostAction.act(user, p, PostActionType.types[:like])
-              rescue PostAction::AlreadyActed
-              end
+              PostActionCreator.like(user, p)
             end
           end
         }