* ignore_unreachable for etcd dir cleanup

ignore_errors ignores errors occur within "file" module. However, when
the target node is offline, the playbook will still fail at this task
with node "unreachable" state. Setting "ignore_unreachable: true" allows
the playbook to bypass offline nodes and move on to proceed recovery
tasks on remaining online nodes.

* Re-arrange control plane recovery runbook steps

* Remove suggestion to manually update IP addresses

The suggestion was added in 48a18284 4
years ago. But a new task added 2 years ago, in
ee0f1e9d, automatically update API
server arg with updated etcd node ip addresses. This suggestion is no
longer needed.

This replaces master with "control plane" in Kubespray docs
because of [1].

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

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

* Fix recover-control-plane to work with etcd 3.3.x and add CI

* Set default values for testcase

* Add actual test jobs

* Attempt to satisty gitlab ci linter

* Fix ansible targets

* Set etcd_member_name as stated in the docs...

* Recovering from 0 masters is not supported yet

* Add other master to broken_kube-master group as well

* Increase number of retries to see if etcd needs more time to heal

* Make number of retries for ETCD loops configurable, increase it for recovery CI and document it