[cern][k8s] Add proxy to master and set cluster-cidr

cherry-picked from: https://review.openstack.org/#/c/592336/2

1. pods with host network can not reach coredns or any svc or resolve their own hostname
2. If webhooks are deployed in the cluster, the apiserver needs to contact them, which means kube-proxy is required in the master node with the cluster-cidr set.

Change-Id: Icb8e7c3b8c75a3ab087c818c8580c0c8a9111d30 story: 2003460 task: 24719

Conflicts: magnum/drivers/common/templates/kubernetes/fragments/configure-kubernetes-master.sh magnum/drivers/common/templates/kubernetes/fragments/enable-services-master.sh