[FEAT] - Adding Templates for Network policies

Adding the following templates for Network Policies to accomplish the following:

• Default deny any Egress+Ingress to namespace.
• Allow haproxy egress to cluster (for kube-dns)
• Allow authservice egress to cluster (for kube-dns & customer applications)
• Allow istio-ingressgateway ingress to haproxy for VirtualService routing
• Allow .Value.selector ingress to authservice for purpose of authservice
• allow monitoring app ingress for authservice+alertmanager UIs & istio sidecar metrics scraping
• allow ingress from inside package namespace

BB issue 427