Expose server side certificate at the APIManager CRD to be mounted in the pod and installed in the apicast processes (staging and production)

Expose the following env vars as CRD fields:

• APICAST_HTTPS_PORT
• APICAST_HTTPS_VERIFY_DEPTH

Expose secret references in APIManager CRD (so you need to create the secret first and reference the name of the secret in the APIManager custom resource).

• APICAST_HTTPS_CERTIFICATE
• APICAST_HTTPS_CERTIFICATE_KEY

Some customers have very strict requirements where TLS needs to be maintained right the way through to the gateway so they cannot terminate on the edge and do so on APIcast instead.