Improve error messages for wrong/missing CRD versions during WATCH

[bcotton]

During the move of a set of CRDs from one version to the next (not a version bump, but a replace e.g. v0_0 -> v1aplha1) I introduced a discrepancy between the CRD that was loaded in the API server vs the schema that was used in the call torunner.WatchKind.

The following is the error that was generated. There was ultimately a 404 being thrown, but the root cause was a missing version on the CRD.

It would be nice to have the watcher check for the existence of the CRD+Version, or catch the 404 and report a better error.

W0118 03:12:32.788684      12 reflector.go:539] github.com/grafana/grafana-app-sdk/operator/informer_kubernetes.go:208: failed to list <unspecified>: the server could not find the requested resource (get components.servicemodel.ext.grafana.com)
E0118 03:12:32.788733      12 reflector.go:147] github.com/grafana/grafana-app-sdk/operator/informer_kubernetes.go:208: Failed to watch <unspecified>: failed to list <unspecified>: the server could not find the requested resource (get components.servicemodel.ext.grafana.com)