Provide automation for multi version CRDs

[howardjohn]

We have alpha and beta versions of networking protos, and they are out of sync. We need to have automation here. There should be a single source of truth with the other versions auto generated.

If we cannot do this, we should at least have checks to ensure they are the same, although this provides a worse devex

cc @jasonwzm

[howardjohn]

We had automation in scripts/validate_crds.py, but reverted when we went from v1 -> beta CRD

[howardjohn]

checking schema is not sufficient, we are missing lots of the docs in the schema such as all our examples, etc that fall out of date.

[howardjohn]

https://github.com/istio/api/issues/3127