Replace kube-master with kube_control_plane (#7256)

This replaces kube-master with kube_control_plane because of [1]:

  The Kubernetes project is moving away from wording that is
  considered offensive. A new working group WG Naming was created
  to track this work, and the word "master" was declared as offensive.
  A proposal was formalized for replacing the word "master" with
  "control plane". This means it should be removed from source code,
  documentation, and user-facing configuration from Kubernetes and
  its sub-projects.

NOTE: The reason why this changes it to kube_control_plane not
      kube-control-plane is for valid group names on ansible.

[1]: https://github.com/kubernetes/enhancements/blob/master/keps/sig-cluster-lifecycle/kubeadm/2067-rename-master-label-taint/README.md#motivation

roles/recover_control_plane/control-plane/tasks/main.yml

@@ -8,22 +8,22 @@
   retries: 6
   delay: 10
   changed_when: false
-  when: groups['broken_kube-master']
+  when: groups['broken_kube_control_plane']
 
-- name: Delete broken kube-master nodes from cluster
+- name: Delete broken kube_control_plane nodes from cluster
   command: "{{ bin_dir }}/kubectl delete node {{ item }}"
   environment:
     - KUBECONFIG: "{{ ansible_env.HOME | default('/root') }}/.kube/config"
-  with_items: "{{ groups['broken_kube-master'] }}"
+  with_items: "{{ groups['broken_kube_control_plane'] }}"
   register: delete_broken_kube_masters
   failed_when: false
-  when: groups['broken_kube-master']
+  when: groups['broken_kube_control_plane']
 
-- name: Fail if unable to delete broken kube-master nodes from cluster
+- name: Fail if unable to delete broken kube_control_plane nodes from cluster
   fail:
-    msg: "Unable to delete broken kube-master node: {{ item.item }}"
+    msg: "Unable to delete broken kube_control_plane node: {{ item.item }}"
   loop: "{{ delete_broken_kube_masters.results }}"
   changed_when: false
   when:
-    - groups['broken_kube-master']
+    - groups['broken_kube_control_plane']
     - "item.rc != 0 and not 'NotFound' in item.stderr"