"As a Curator, I want to see the effects of undoing a revision before I do it, so that I can decide whether it improves the content."
Returns the diff that would be applied if the revision were undone.
Request body: none
Notable request headers: none
200 - Success; the body contains the reverse diff
403 - Forbidden; the user is not allowed to view the reverse diff of this revision
404 - There is no such revision
Notable response headers: none
Response body: JSON, object with these properties:
diff: reverse diff for this revision; an array of diff objects as defined for T231347