"As a Curator, I want to compare two revisions that differ in non-main slots, so that I can see all changes to the page."

The endpoint defined in T231347: Curator compares revisions doesn't support differences in non-main slots. This user story is to enhance the output of that endpoint with information about non-main slots.

The endpoint is otherwise unchanged, with the following output format:

Body: JSON, an object with the following fields:

• from: object containing {id: first ID, identical to id parameter}
• to: object containing {id: second ID, identical to other parameter}
• diff: difference object for main slot; may be empty
• slots: an object mapping slot role names to difference objects