Optimize `rm` action

[aidan-mundy]

• rm and autoclean should not cause any actions other than rm
• 'autoclean' should not trigger an rm action on an alias because that is redundant
• rm should proceed as far as possible, even if some config vars cannot be parsed
  • On an image, config vars in the args section do not affect the rm task. Any tag without a config var should also be removed.
  • On a job, none of the config vars affect the rm task.
  • On a compose, all config vars affect the rm task,

A caveat here is that fixing 1&2 makes 3 a much more noticeable problem.

[aidan-mundy]

Thinking about solutions for item 3, it appears to me that dobi would benefit from a much more comprehensive state management system, similar to how terraform manages its state.