feat: Migration to the latest camera/mobile_scanner (openfoodfacts#6075)

* Migration to the latest camera/mobile_scanner

* Bump minSdkVersion (Android)

* Minor change

packages/scanner/ml_kit/lib/src/mobile_scanner_controller.dart

@@ -0,0 +1,142 @@
+import 'package:flutter/material.dart';
+import 'package:mobile_scanner/mobile_scanner.dart';
+import 'package:torch_light/torch_light.dart';
+
+class CustomScannerController {
+  CustomScannerController({
+    required MobileScannerController controller,
+  })  : _controller = controller,
+        _torchState = TorchState(),
+        _availableCamerasState = AvailableCamerasState(),
+        _cameraFacingState = CameraFacingState() {
+    _detectTorch();
+  }
+
+  final MobileScannerController _controller;
+  final TorchState _torchState;
+  final AvailableCamerasState _availableCamerasState;
+  final CameraFacingState _cameraFacingState;
+
+  bool _isStarted = false;
+  bool _isStarting = false;
+  bool _isClosing = false;
+  bool _isClosed = false;
+
+  Future<void> start() async {
+    if (isStarted || _isStarting || isClosing) {
+      return;
+    }
+
+    _isStarting = true;
+    _isClosed = false;
+    try {
+      _controller.addListener(_onControllerChanged);
+      await _controller.start();
+      _isStarted = true;
+
+      if (isTorchOn) {
+        // Slight delay, because it doesn't always work if called immediately
+        Future<void>.delayed(const Duration(milliseconds: 250), () {
+          turnTorchOn();
+        });
+      }
+      _isStarting = false;
+    } catch (_) {}
+  }
+
+  void _onControllerChanged() {
+    _availableCamerasState.value = _controller.value.availableCameras ?? 0;
+    _cameraFacingState.value = _controller.facing;
+  }
+
+  MobileScannerController get controller => _controller;
+
+  bool get isStarted => _isStarted;
+
+  bool get isClosing => _isClosing;
+
+  bool get isClosed => _isClosed;
+
+  Future<void> stop() async {
+    if (isClosed || isClosing || _isStarting) {
+      return;
+    }
+
+    _isClosing = true;
+    _isStarting = false;
+    _isStarted = false;
+    try {
+      await _controller.stop();
+      _controller.removeListener(_onControllerChanged);
+      _isClosing = false;
+      _isClosed = true;
+    } catch (_) {}
+  }
+
+  bool get hasTorch => _torchState.value != null;
+
+  ValueNotifier<bool?> get hasTorchState => _torchState;
+
+  bool get isTorchOn => _torchState.value == true;
+
+  void turnTorchOff() {
+    if (isTorchOn) {
+      _controller.toggleTorch();
+      _torchState.value = false;
+    }
+  }
+
+  void turnTorchOn() {
+    if (!isTorchOn) {
+      _controller.toggleTorch();
+      _torchState.value = true;
+    }
+  }
+
+  void toggleTorch() {
+    if (isTorchOn) {
+      turnTorchOff();
+    } else {
+      turnTorchOn();
+    }
+  }
+
+  ValueNotifier<int> get availableCameras => _availableCamerasState;
+  ValueNotifier<CameraFacing> get cameraFacing => _cameraFacingState;
+
+  void toggleCamera() {
+    _controller.switchCamera();
+    if (_controller.facing == CameraFacing.front) {
+      _torchState.value = null;
+      _cameraFacingState.value = CameraFacing.front;
+    } else if (_controller.facing == CameraFacing.front) {
+      _torchState.value = false;
+      _cameraFacingState.value = CameraFacing.back;
+    }
+  }
+
+  Future<void> _detectTorch() async {
+    try {
+      final bool isTorchAvailable = await TorchLight.isTorchAvailable();
+      if (isTorchAvailable) {
+        _torchState.value = false;
+      } else {
+        _torchState.value = null;
+      }
+    } on Exception catch (_) {}
+  }
+
+  Future<void> dispose() => _controller.dispose();
+}
+
+class TorchState extends ValueNotifier<bool?> {
+  TorchState({bool? value}) : super(value);
+}
+
+class AvailableCamerasState extends ValueNotifier<int> {
+  AvailableCamerasState() : super(0);
+}
+
+class CameraFacingState extends ValueNotifier<CameraFacing> {
+  CameraFacingState() : super(CameraFacing.back);
+}