[feat] Support for GitHub's New UI

[ToshihitoKon]

Thank you for creating this wonderful extension!

GitHub recently released a preview of their new UI for Pull Request review pages. I've noticed that the file icons in the sidebar of the review pages are not being applied with the extension's material icons.

Old UI

New UI

Would it be possible to add support for GitHub's new UI? I've attached screenshots showing the difference between the current behavior and the expected material icons display.

Thank you for your consideration and for maintaining this great extension!