Notify about dereferenced collections.

Otherwise zanshin won't be notified about dereferenced collections.
LIST: filter referenced collections also with an invalid toplevel collection

Otherwise we get unwanted collections from a toplevel list if another session
referenced the collection.
NotificationSource: set the session to filter referenced notifications.
NotificationSource: Send notifications to referenced collections.

We no longer rely on referenced collections being monitored.
Do not cleanup all entries for a resouce if one tag is updated.

If we delete all entries for one resource, than we loose the remote id
for the tags. Only delete the specific entry, that is inserted/updated
afterwards.

KOLAB: 3541
Merge remote-tracking branch 'kolab/dev/fix_tagremote' into kolab/integration/1.12.0