CW-315-Add-a-toast-message-to-enable-denied-permissions-in-device-settings (#1157)

* add permission handler

* localization

* minor fixes

---------

Co-authored-by: OmarHatem <omarh.ismail1@gmail.com>

lib/utils/permission_handler.dart

@@ -0,0 +1,32 @@
+import 'package:cake_wallet/generated/i18n.dart';
+import 'package:cake_wallet/utils/show_bar.dart';
+import 'package:flutter/cupertino.dart';
+import 'package:permission_handler/permission_handler.dart';
+
+class PermissionHandler {
+  static Future<bool> checkPermission(Permission permission, BuildContext context) async {
+    final Map<Permission, String> _permissionMessages = {
+      Permission.camera: S.of(context).camera_permission_is_required,
+    };
+
+    var status = await permission.status;
+
+    if (status.isDenied) {
+      status = await permission.request();
+    }
+
+    if (status.isPermanentlyDenied || status.isDenied) {
+      String? message = _permissionMessages[permission];
+      if (message != null) {
+        showBar<void>(context, message);
+      }
+      return false;
+    }
+
+    if (status.isGranted) {
+      return true;
+    }
+
+    return false;
+  }
+}