Added Performance overlays in developer options

lib/storage/devTools/devToolsSettings.dart

@@ -0,0 +1,15 @@
+import 'package:json_annotation/json_annotation.dart';
+
+part 'devToolsSettings.g.dart';
+
+@JsonSerializable()
+class DevToolsSettings {
+  bool showPerformanceOverlay;
+  bool checkerboardOffscreenLayers;
+  bool checkerboardRasterCacheImages;
+
+  DevToolsSettings({required this.showPerformanceOverlay, required this.checkerboardOffscreenLayers, required this.checkerboardRasterCacheImages});
+
+  factory DevToolsSettings.fromJson(Map<String, dynamic> json) => _$DevToolsSettingsFromJson(json);
+  Map<String, dynamic> toJson() => _$DevToolsSettingsToJson(this);
+}