Upgrade CRD from v1beta1 to v1

[jasonwzm]

Upgrade CRDs to v1 and remove the use of v1beta1 CRD client code in Istio.

kubernetes/kubernetes#79604 mentions v1beta1 will not be served starting Kubernetes 1.19. So with the current release cadence, we need to finish it by Istio 1.8.

[howardjohn]

so there is only 1.16-1.18 where both are supported? that does give us a pretty tight window... that's say more aggressive than other apis.

We may need to support both options at once, not sure his much effort that would involve

[jasonwzm]

Yes. So we have roughly a year to make this fully work.

Yea, probably a lot of work. They provide conversion funcs which we leverage though.