Moderate diff

This module makes it so a content moderator can approve or reject content updates from the diff page.

The most relevant view when a moderator is reviewing content oftentimes will be the one that shows the changes from most recently proposed new version compared to the currently published revision. For example, if a long piece of content were approved, and then a one-character change were made to it, it's almost useless to review the full content versus some version of what diff module can provide, so the moderation control form should be available on diffs revisions.

Starting as a separate module to get it done, but ready to be incorporated into Diff module if this issue is accepted: https://www.drupal.org/project/diff/issues/3335901