Filtering and sorting needs to operate on unstructured data. It also
needs to operate after the parallel partitioner, higher in the store
stack. This means that the proxy Store needs to return raw, unstructured
data up to the partitioner. This change moves all conversions from
unstructured Kubernetes types to apiserver objects up from the proxy
store into the partitioner.
The use of AddNamespaceConstraint was removed in e35b8304 of
rancher/rancher, so there is no possibility of there being a namespace
constraint in the request context. Remove the unused function and the
unused codepath from the rbac store.
