fix(commands): refresh Solution Explorer after cleaning bin/obj

[CalvinAllen]

Summary

• Sends the standard VSStd97CmdID.Refresh command to each cleaned project's IVsUIHierarchy after deleting bin/obj.
• Same code path as right-click → Refresh, so stale "Show All Files" nodes disappear without an unload/reload.
• No Solution Explorer selection change, no visible collapse/expand flash.

Test plan

• Open a solution with Show All Files enabled on a project that has built bin/obj content.
• Run Super Clean on the solution — verify the bin/obj nodes disappear from Solution Explorer immediately (no unload/reload needed).
• Run Super Clean on a single project — verify the same.
• Verify Web Site projects are still skipped with the existing notification.
• Verify the active Solution Explorer selection is unchanged after Super Clean completes.

Resolves #33