Currently the heat charm instance runs heat-api and
heat-engine services or heat-api-cfn or heat-engine
services. Change heat charm to deploy heat-api,
heat-api-cfn, heat-engine containers.
Change the ingress relation to use traefik-route
interface instead of ingress interface so that the
traefik configuration for heat-api and heat-api-cfn
serive can be written by charm.
Add heat-api-cfn pebble container handler and update
service endpoints accordingly.
Remove heat-config interface and corresponding handlers.
Change-Id: I391f8d4ffefcebdb2423fcc1947590ca906d711a
4a473da7fe