Dismiss selected file match highlight on cursor movement

[dmitrivMS]

Fixes #43928

[Copilot]

Pull request overview

This PR implements functionality to automatically dismiss the selected search result highlight when the user moves the cursor in the editor. It addresses issue #43928 by adding cursor position monitoring that clears the highlight upon detecting cursor movement.

Key changes:

• Imports MutableDisposable to manage the lifecycle of the cursor position listener
• Adds a cursor position listener that monitors the active editor and clears the search match highlight when the cursor moves
• Sets up the listener to be recreated whenever the active editor changes