This PR fixes issues with closing the WireGuard watcher by adjusting its asynchronous invocation and synchronization.
Update tests in wg_watcher_test.go to launch the watcher in a goroutine and add a delay for timing.
Modify wg_watcher.go to run the periodic handshake check synchronously by removing the waitGroup and goroutine.
Enhance conn.go to wait on the watcher wait group during connection close and add a note for potential further synchronization
Fix WireGuard watcher related issues
- Fix race handling between TURN and Relayed reconnection
- Move the WgWatcher logic to separate struct
- Handle timeouts in a more defensive way
- Fix initial Relay client reconnection to the home server
