[WIP] Work in self-signed certificates for the Frontend.

[mociarain]

What this PR does

This PR adds the necessary infrastructure and wiring for the frontend to become publicly addressable via Istio using a self-signed certificate.

Special notes for your reviewer

To test just build a svc cluster and deploy/redeploy the frontend then run:

export INGRESS_HOST_EXTERNAL=$(kubectl -n aks-istio-ingress get service aks-istio-ingressgateway-external -o jsonpath='{.status.loadBalancer.ingress[0].ip}')

curl -kv -HHost:frontend \
    --resolve "frontend:443:$INGRESS_HOST_EXTERNAL" \
    "https://frontend:443/subscriptions/00000000-0000-0000-0000-000000000000?api-version=2.0"

TODO:

• It's getting to the envoy proxy but not actually speaking to the FE. I need to open up some more logging and see what's going on. https://learn.microsoft.com/en-us/azure/aks/istio-meshconfig