[Proposal] add a search/filter bar for files in PR "Files Changed" page

[Technius]

Feature Description

For PRs that involve many files, it would be great if the "Files Changed" page had a search bar above top of the file tree view. This search bar could be used to filter the files shown in the tree view to make navigation easier.

Screenshots

A search bar above the file tree view (right above the "packages" folder in the screenshot) would be very convenient.