Consider removing the `docker` command and it's subcommnads

[surovic]

Polytracker's docker command adds the external dependencies, maintenance weight and arguably adds very little utility compared to using bare docker CLI commands. Maybe we should get rid of the polytracker docker command. Opinions welcome!

[surovic]

Another alternative is to create a separate repository (e.g. polytracker-utils) for helper and convenience commands we don't really want to commit to maintain to the same degree as the core ones.