Improve file labeling in Git diff view – show file name first, then path

[kleinpetr]

In the Git diff view, deeply nested files are hard to identify at a glance because the full path is shown, making the actual file name hard to spot without expanding the panel. It would improve readability if the file name was shown first, followed by the relative path in smaller text, similar to how VS Code handles it.

[SomeoneToIgnore]

#26097