Map Scala collections to Java collections and the other way round

[codepitbull]

Description

During our discussions we realized that with Scala 3 it is possible to do a lot of mapping with a minimum of allocation actually happening. This makes it possible again to have full API-mappings.

Note: Since converting Vert.x-objects is taken care of via implicit classes which eliminates the need for converting every object contained in the collections eagerly.

Acceptance Criteria

Generated methods contain the Scala-collections in both directions.