Mobile push notification handling was reorganized to run through the message notification process instead of the channel area. This internal cleanup should reduce performance overhead in mail-related operations and make future notification improvements easier.

Task: https://www.odoo.com/web#id=1838693&view_type=form&model=project.task&action=333&active_id=965&menu_id=4720

Linked to https://github.com/odoo/odoo/pull/24374