The registry abstraction is unnecessary and adds direct coupling to the
core types. By using a wrapper, we carry through the default
implementations of the non-mutating operations. The DeleteCollection
method is explicitly patched out since it cannot be correctly
implemented on the storage currently.
As a result, TableConvertor is now exposed.
A few other minor refactorings
* Corrected the case of some variables
* Used functions instead of methods for several helper methods
* Removed the legacy Deleter - service was the only remaining consumer
Kubernetes-commit: 110b064d630ca39220696225dd597e7d33b95f4f
7b21554cfc