More Networkpolicies

[timtorChen]

1. Follows the least priviledge principle and add Neworkpolicy on each namespace.
2. For appliction use hostNetwork: true, Networkpolicy will not work, thus extra treatments should be considered:

• Add kube-rbac-proxy sidecar in front of node-exporter.
• Add CNI plugin multus-cni enabling multiple network interface for cephcluster.