Returns unawarded user ids (need to be saved) and the count.

def get_unawarded_user_ids(self, db_read=None):
        """
        Returns unawarded user ids (need to be saved) and the count.
        """
        db_read = db_read or self.db_read

        already_awarded_ids = self.get_already_awarded_user_ids(db_read=db_read)
        current_ids = self.get_current_user_ids(db_read=db_read)
        unawarded_ids = list(set(current_ids) - set(already_awarded_ids))
        unawarded_ids_count = len(unawarded_ids)

        logger.debug(
            '→ Badge %s: %d users need to be awarded',
            self.slug,
            unawarded_ids_count)

        return (unawarded_ids, unawarded_ids_count)