detect cluster ingress in helm2

[maire-kehoe]

In the helm2 script check_and_deploy_helm.sh,
for clusters that have disabled NodePort but that do have cluster ingress enabled,
detect and update a Kubernetes Ingress resource with values reflecting the cluster ingress configuration.

Roughly, the steps are
if the Helm chart values has: ingress
then set: ingress.enabled=true
and replace chart strings cluster-ingress-subdomain and cluster-ingress-secret
with the respective cluster ingress host and cluster ingress secret.
That is, for each host at a path like ingress.hosts[0]
that has a value like "hello-app.cluster-ingress-subdomain",
change it to a value like "hello-app.example.com".
For each tls host at a path like ingress.tls[0].hosts[0]
that has a value like "hello-app.cluster-ingress-subdomain",
change it to a value like "hello-app.example.com".
For each tls secret at a path like ingress.tls[0].secretName
that has a value like "cluster-ingress-secret",
change it to a value like "example-tls-secret".

Related to the proposed changes in the hello-helm repo:

• detect cluster ingress
  https://github.com/open-toolchain/hello-helm/pull/5

Also related to the similar previous change for non-Helm kubectl deploys:

• Add ingress processing for kubernetes cluster
  Add ingress processing for kubernetes cluster #65

[maire-kehoe]

Note this code needs updates similar to:

• Manage APP_URL with an ingress context to use runtime information
  https://github.com/open-toolchain/commons/pull/71/files

[maire-kehoe]

Likewise need fix: #72