Comment serialization cleanup part 5: Convert DiffReviewableCollection
Review Request #13659 — Created March 21, 2024 and submitted — Latest diff uploaded
This change converts the DiffReviewableCollection to Typescript and
spina. While not truly necessary for the DiffFile cleanup, it is used in
here, and having this makes it easier to use automated tooling to find
the DiffFile uses.
Ran js-tests.