- Add RBAC permission to list deployments in knative-serving namespace
- Ensure service account has new permission
- Update documentation to instruct people to add the ability to list
  deployments in knative-serving
- Add get_cluster_role_bindings delegation to kubeclient
- Add KnativeVersionRoleBindingFinder
- Add knative_version_role_binding to KubernetesNamespace prereq
- Update tests for knative version role and binding

Relates to https://gitlab.com/gitlab-org/gitlabktl/issues/17Co-Authored-By: Matt Kasa <mkasa@gitlab.com>