Before migration is run flags code is evaluated. It is causing error:
```
NoMethodError: undefined method `require_message' for an instance of Flag (NoMethodError)
Did you mean? require_dependency
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activemodel-7.1.3.4/lib/active_model/attribute_methods.rb:489:in `method_missing'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-7.1.3.4/lib/active_record/relation/delegation.rb💯in `each'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-7.1.3.4/lib/active_record/relation/delegation.rb💯in `each'
/var/www/discourse/app/models/post_action_type.rb:64:in `reject'
```
The solution is to temporarily fall back to old column name - custom_type
Allow admin to create custom flag which requires an additional message.
I decided to rename the old `custom_flag` into `require_message` as it is more descriptive.
`after_commit` should be used before refreshing processes to be sure that the database is already updated.
Also, MessageBus is used instead of events as MessageBus works correctly with many processes;
Allow admin to create custom flag which requires an additional message.
I decided to rename the old `custom_flag` into `require_message` as it is more descriptive.
Continued work on moderate flags UI.
In this PR admins are allowed to change the order of flags. The notify user flag is always on top but all other flags can be moved.
