Add info that the attendees will not be notified unless the current user is owner of the calendar AND organizer of the event

[DeepDiver1975]

          Maybe at least adding an info that the attendees can't be notified on a shared event? That only attendies added by calendar owner will be notified? Now it's really unclear when the notification works and when not.

Somewhere here:

Originally posted by @lubomirblazekcz in https://github.com/owncloud/core/issues/40982#issuecomment-1752820043