Define a mapping between REST resource name and kind/apiVersion

Allows clients to abstractly map user input to generic resource
paths as per docs/api-conventions.md

Extracted from #2000 and supports #1958
RESTPath? RESTCollectionPath? Also can you add a comment explaining how much of the path one can expect to see here? Is it /api/v1betaX/resourcetype/? or just resourcetype?