Support docker registry and expose Docker apps in Murano Catalog

Docker is a fast growing space aroun containers and applications via containerization. Docker images which are sometimes called apps as they can contain preinstalled and preconfigured apps which start on Docker container start should be exposed in Murano App catalog. It looks pretty staightforward to do: have an Application Docker containers host and other apps with Docker images. So that in environment you can have VM with Docker and images installed into it. Docker has port mappings so we need to find out how to show this in UI so user can do port mappings in UI or programmatically in Murano PL.