Provide Drush command for asset update.

Requesting an early review.
Note: These commands can be further improved.

This is working as expected. The finalized version updates in the Acquia DAM system, and the Drush command retrieves the finalized version without needing to manually click the “Check for update” button each time.

Committing so we can get this into the next release. However, it'd be good to follow up with some tests to verify its functionality beyond a cursory review.