Mount certificates rather than building them into containers

Currently SSL certificates and CA are being built directly into various containers (voltha, ponsim, maybe others). This is undesirable from a security and deployment perspective.

The recommended solution is to mount the certificates into the containers at runtime.

This involves:

• Determining names for the certificates to be mounted
• Changing the container build process to not include these files
• Creating docker compose/kubernetes config/helm charts that mount the certificates into running containers
• Documenting how to generate cert in both testing and deployment environments