Generate sechub client utility classes through openapi generator

[hamidonos]

Situation

The current sechub client offers utility classes which offer convenience in using the client.

Wanted

We want to keep these utility functions and classes when we migrate to the new openapi generator.

Solution

• Generate all necessary sechub utility classes as part of the actual client generation. This should be possible through the gradle openapi generator plugin directly or by writing a custom gradle generator plugin.