With this commit we try to improve the way the events are displayed
to the user. Now, an event is displayed for each attendee of the event
that are selected in the filter. These events are displayed correctly
based on the status of the attendee in the event.
The colors displayed for the events now represent the attendees and not the
organizer.
If an attendee edit an event, it is edited for all others attendees.
Also, when an attendee that is not the organizer try to delete the event,
then the event is now declined in place of being deleted. If the organizer
delete the event, it is deleted for all attendees.
In case of an event where all attendees have declined it but the organizer,
the organizer see now a danger icon before the name of the event and it's
outlined and not filled with color, no matter of the actual status of the
organizer in the event.
task-2196775
COM PR: odoo/odoo#55190
ENT PR: odoo/enterprise#12196
UPG PR: odoo/upgrade#1532
Jérémy Hennecart
ac13964244