Rename ansible groups to use _ instead of - (#7552)

* 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

contrib/terraform/aws/templates/inventory.tpl

@@ -11,7 +11,7 @@ ${public_ip_address_bastion}
 ${list_master}
 
 
-[kube-node]
+[kube_node]
 ${list_node}
 
 
@@ -19,10 +19,10 @@ ${list_node}
 ${list_etcd}
 
 
-[k8s-cluster:children]
-kube-node
+[k8s_cluster:children]
+kube_node
 kube_control_plane
 
 
-[k8s-cluster:vars]
+[k8s_cluster:vars]
 ${elb_api_fqdn}