Add "Reveal in Explorer View" for WIP files in the graph and commit details WIP panels

[eamodio]

Summary

Adds a Reveal in Explorer View context-menu action to working (WIP) file rows in the Commit Graph details WIP panel and the Inspect (commit details) WIP panel, letting users jump from a working change directly to that file's location in VS Code's Explorer view.

Impact

Anyone reviewing working changes in a WIP panel can now quickly locate the underlying file in the workspace tree — parity with the file actions already offered there (Open File, Copy Path, etc.). Applies to staged, unstaged, and conflicted WIP files in both panels.

Validation

1. Make some working changes in a repo so the WIP panel lists changed files.
2. Open the Commit Graph; with the working-tree row in focus, right-click a WIP file in the details WIP panel.
3. Confirm Reveal in Explorer View appears under the Open File group and reveals/selects the file in the Explorer sidebar.
4. Confirm it shows for staged, unstaged, and conflicted files, and does not show on committed file rows.
5. Repeat in the Inspect (commit details) view's WIP panel.

Risk

Low — purely additive context-menu item gated to WIP file rows; reuses the existing file-command registration and VS Code's core reveal command. No change to existing actions.