subtests.docker_cli: Add detach and interaction test

This pull request implements the https://github.com/autotest/autotest-docker/pull/192 inside the test instead of framework to give it time to stabilize before turning it into framework. I believe that this implementation is cleaner and easier to follow than hybrid implementation from https://github.com/autotest/autotest-docker/pull/194

Kind regards,
Lukáš
Still seems like an awful lonely class.  OOooohhhhh, now I get why it's seeming so strange to me:  This class descends from a type of "do some docker thing" but distorts it to 'do some shell thing'.  It's counter-productive to cut a square-peg for a round hole, when you have a Peg-o-matic you can code for any shape shape.

As ``InteractiveAsyncDockerCmd`` grows, this class will just fill up with workarounds to "undo-ing" parent behavior.  Just forget about the DockerCmd hierarchy completely, it's needlessly constricting for this use.  Instead, write a new class  that only does async. bash, exactly how you like it.   Even if it happens to look like ``DockerCmdBase`` today,  it will be completely free to independently grow in it's own direction.