make crowbar machines aliases also output node name

This is useful for seeing the mapping between node name and alias.

I would have made this optional but sadly `crowbar_machines` does not support options for subcommands.
Sorry @tboerger but you're wrong - without this hunk, it is impossible to delete an alias from a node, from both the per-node editing view and the bulk edit view.  Just try it.  In the former, it results in an error:

    Failed to save d52-54-00-03-fb-01.crowbar.site: Alias not saved because it did not conform to valid DNS hostnames: