Make crd-generator usable at runtime

[metacosm]

This could help with Quarkus integration and make it possible for users to generate CRDs via other means than APT (e.g. maven plugin).

[manusa]

Does this translate into exposing the CRD-Generator core logic as an API?
If so, sound great to me. I can think of many different projects that would benefit from this.

[metacosm]

Yes, that would be the plan.