Users who delete a collection expect all resources to be deleted, and
users can also delete an uninitialized resource. To preserve this
expectation, DeleteCollection selects all resources regardless of
initialization.
The namespace controller should list uninitialized resources in order to
gate cleanup of a namespace.
If the namespace controller encounters an error trying to delete a
single GroupVersionResource, add the error to an aggregated list of
errors and continue attempting to delete all the GroupVersionResources
instead of stopping at the first error. Return the aggregated error list
(if any) when done. This allows us to delete as much of the content in
the namespace as we can in each pass.
