refactor: revert autoStart and onDetect. See changelog for more

-import 'dart:async';
-
 import 'package:flutter/material.dart';
 import 'package:mobile_scanner/mobile_scanner.dart';
-import 'package:mobile_scanner_example/scanner_button_widgets.dart';
-import 'package:mobile_scanner_example/scanner_error_widget.dart';
 
 class BarcodeScannerSimple extends StatefulWidget {
   const BarcodeScannerSimple({super.key});

@@ -120,6 +120,7 @@ class MobileScanner extends StatefulWidget {
 
 class _MobileScannerState extends State<MobileScanner> {
   late final controller = widget.controller ?? MobileScannerController();
+
   /// The current scan window.
   Rect? scanWindow;