Use operation hooks instead of deprecated model hooks

See the discussion in #824. We were not able to remove deprecated model hooks because embedded relations are still relying on them.

There is a feature for inst.triggerParent in embedsMany that needs more consideration and possibly a rewrite for embedded relations to continue work. It is for updating the parent model if any changes are made to the relation. This part needs a redesign and rewrite to consider the different cases and to make it all consistent.

We should rewrite inst.triggerParent to not depend on deprecated hooks, for example using the approach outlined in https://github.com/strongloop/loopback-datasource-juggler/commit/d0cc791bc65e5ee7d2447698539da1d1ca0591ee

cc @jannyHou @Amir-61 @superkhau

Beginne mit der Diskussion in #824 und untersuche den Pfad für eingebettete Beziehungen rund um inst.triggerParent. Vergleiche sein aktuelles Verhalten mit dem Ansatz in Commit d0cc791bc65e5ee7d2447698539da1d1ca0591ee. Als erledigt gilt die Aufgabe, wenn eingebettete Beziehungen ihr übergeordnetes Element weiterhin konsistent aktualisieren, ohne auf veraltete model hooks angewiesen zu sein.