mtda-cli as a docker image

[chombourger]

With the protocol breakage expected with the Pyro 4 to 5 version change or the potential switch to gRPC (#524), we may want to build and upload a mtda-cli container image

[fmoessbauer]

We could do something similar like kas-container. By that, the mtda-cli would be wrapped in a way that is mostly transparent to the user. However, the effort to properly support this is not to be underestimated (we learned that at kas the hard way).