R1:24305cadb902

Hide the "large" diff warning on "very large" diffs

Summary:
Ref T13110. Ref T13130. When a revision is "large" (100 - 1000 files) we hide the actual textual changes by default. When it is "very large" (more than 1000 files) we hide all the changesets by default.

For "very large" diffs, we currently still show the "large" warning, which doesn't really make sense since there aren't any actual changesets.

When a diff is "very large", don't show the "large" warning.

Test Plan:
- Viewed a small diff…