Add the ability to run platform as daemon

[gitbuda]

https://discourse.memgraph.com/t/memgraph-lab-as-a-separate-image/223

There is a need to use Memgraph Lab on Fedora (any Linux distro), one way is to run memgraph-platform in the daemon mode. It would be great if just providing -d Docker flag would do the magic. If that's not possible, at least some user-friendly parameters would also be great, e.g., docker run -d ... memgraph/memgraph-platform --daemon. I saw this example https://github.com/fr3nd/docker-supervisor/blob/master/entrypoint.sh on a couple of places as a common practice with Docker (in general, additional shell script to manage the options).