Validate `*-submission` events (SET) created by zustelldienst against SET schema

The zustelldienst creates *-submission events here. These *-submission events should be valid with the SET-payload schema. To ensure these schemas are fulfilled, validate each *-submission event against it.

This ticket is a follow up of #1293 (closed). In the first step only new introduced *-reply events should be validated. Now all events incl. *-submission events should be validated.

Hint

The Java SDK already has a solution to verify events. This solution can be adopted in zustelldienst.

Akzeptanzkriterien

1. zustelldienst cannot create invalid *-submission events.

Durchführungsplan (von Entwickler:in bei Umsetzungsplanung auszufüllen)

• Analyse solution of Java SDK.
• adopt the solution in zustelldienst.
• Create tests that verify that already created *-submission events are correct and valid.