When synchronizing microsoft calendar events, if the event is permanent
Microsoft says the endDate is "0001-01-01": we save that and this causes
an error when it is being parsed in javascript since we require a date
with higher than 1000 years in require('web.field_utils').parseDate
function.

With this changeset, we do not set endDate if the type of the event is
not endDate (as shown[^1] in the documentation endDate only makes sense
for event of type endDate).

[^1]: https://docs.microsoft.com/en-us/graph/outlook-schedule-recurring-events#recurrence-ranges

opw-2479029
fixes #69481
closes #69944

Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>

    Turn off calendar.attendees notification during synced_events creation
    to improve performances. The calendar notification are only computed
    once after all the synced events have been created.

    Add a flag in microsoft_calendar.js to avoid retriggering synchronization
    while navigating the calendar view if the past synchronization is still
    pending.

closes odoo/odoo#67192

Signed-off-by: Raphael Collet (rco) <rco@openerp.com>