Ensure that kubectl get works with downstream resources

Commit a198a62 introduced a dependency linking the Kube API versions to the implementation
of watching resources used in kubectl.  This removes that dependency and allows conversion
to be handled by the ObjectConvertor defined in the kubectl factory.

@lavalamp review please
So this whole change that I made probably would have been avoided if "versioned" weren't totally ambiguous. It was meant as "requiresVersionedInput" but I read it as meaning "emitsVersionedOutput". This function should stay, but it should be renamed to something that's not ambiguous.