Notifies the subscriber after Check Database

[Arthur-Milchior]

See #16941 for the details. This issue can be closed specifically when, after a "check database" ends, ChangeManager.notifySubscribers is called with a OpChanges where all values are set to true.

Ideally, it'd be nice if you could only do the notification if anything was changed in the collection. In practice, I fear it'll be hard to do.