Refactor WorkerImpl to integrate logging, enhance testing with mocks, improve timeout and error handling, and add worker ID generation.

finlog_app/app/lib/main.dart

@@ -78,9 +78,6 @@ class _MyHomePageState extends State<MyHomePage> {
             ),
             TextButton(
               onPressed: () {
-                print(
-                  "active workers: ${App.service<Worker>().getActiveWorkers().length}",
-                );
               },
               child: Text("Print workers"),
             ),