This adds a generic implementation of a lister, and uses it to replace
the template code in generated listers. The corresponding templates
are no longer used and are removed.
Listers are reduced to their interfaces (non-namespaced and namespaced
if appropriate), their specific structs, and their constructors. All
method implementations are provided by the generic implementation. The
dedicated interface is preserved so that each lister can have its own
set of methods (e.g. the method returning the namespaced lister if
appropriate), and the dedicated struct is preserved to allow
expansions to be defined where necessary.
The external interface is unchanged and doesn't expose generics.
Signed-off-by: Stephen Kitt <skitt@redhat.com>
Kubernetes-commit: 2e9adcd14aae27394238291fa08fb603bf2f3e77
