Support docker contexts

[csadorf]

User story

As a user I expect that aiidalab-lauch respects the activated docker context so that I can use my preferred docker runtime without work-arounds.

For example, as a Mac user you might want to use colima as your docker runtime rather than Docker Desktop (see here for underlying motivation).

Additional context

We use docker-py to interact with the docker runtime which currently does not respect the configured context.