Communication on events is considered as standard: receive a confirmation
at subscribe and receive reminders. We therefore set default event mail
on both template and event models
* event.type has default communication with 3 emails;
* event.event has default communication when no event type is chosen. When
a template (event.type) is chosen its configuration is more important;
Task-2488019
PR odoo/odoo#68901
qmo-odoo
b18efd703c