[nx-container] Wrap Docker output in a group

[avaly]

When running this command in Github Actions, all the logs except the Docker command & output are wrapped in collapsible areas (groups). The Docker command & output are sometimes large & noisy (especially if using a remote registry cache - cache-from / cache-to). I think these should also be wrapped in a group.

[gperdomor]

@avaly I have no control about the output of docker build commands, there is nothing to do from our side :(