Add file explorer filter to show only changed files when viewing git branch diff

[teooliver]

When using the git:branch diff command, it would be helpful to have an option to filter the file explorer to show only the files that have changed in the diff.

Current Behavior:

• git:branch diff opens the Project Diff tab
• The file explorer continues to show all files in the project

Proposed Behavior:

When viewing a branch diff, add an option (toggle or automatic) to filter the file explorer to display only files that have changed
This could work similarly to how the "Git Panel" displays the files with changes

Use Case

When reviewing changes across branches, especially on larger projects, it can be helpful to focus on just the modified files without the visual noise of unchanged files. This would make it easier to:

• Navigate between changed files
• Get a quick overview of which files were affected
• Maintain context while reviewing branch differences

Possible Implementation Ideas:

Add a toggle button in the file explorer to enable/disable this filter
Automatically filter when branch diff is active, with an option to show all files