Allow a notification to be hidden in the notification settings

Currently, all the notifications are presented to all users.

This can lead to some notifications configuration to be presented to users that will never receive them (e.g., security notifications dedicated to admins).

Therefore, it is interesting to provide a mechanism to hide a given notification from the user notification configuration.

Possible implementation: Provide a new method in RecordableEventDescriptor, for instance canConfigure(UserReference):boolean. and use this value to decide if a notification should be presented to the user in the notification configuration screen.