* rename ansible groups to use _ instead of -
k8s-cluster -> k8s_cluster
k8s-node -> k8s_node
calico-rr -> calico_rr
no-floating -> no_floating
Note: kube-node,k8s-cluster groups in upgrade CI
need clean-up after v2.16 is tagged
* ensure old groups are mapped to the new ones
* containerd docker hub registry mirror support
* add docs
* fix typo
* fix yamllint
* fix indent in sample
and ansible-playbook param in testcases_run
* fix md
* mv common vars to tests/common/_docker_hub_registry_mirror.yml
* checkout vars to upgrade tests
Cristian Calin
Daniil Muidinov
Gregor Krmelj
Sergey