Use the new `DocumentHelperMixin` to refactor the `._db_name` property in post_save signal handlers.
Use the new `DocumentHelperMixin` to refactor the `._db_name` property in post_save signal handlers.

1flow/1flow,WillianPaiva/1flow,WillianPaiva/1flow,1flow/1flow,1flow/1flow,WillianPaiva/1flow,1flow/1flow,WillianPaiva/1flow,1flow/1flow,WillianPaiva/1flow