basic configurations (global providers and consts)

lib/config/design_config.dart

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+class DesignConfig {}

lib/constants/app_strings.dart

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+class AppStrings {}

lib/models/enums.dart

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+enum AppState {
+  idle,
+  busy,
+  failed,
+}

lib/providers/core_provider.dart

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+import 'package:didvan/models/enums.dart';
+import 'package:flutter/cupertino.dart';
+
+class CoreProvier with ChangeNotifier {
+  AppState _appState = AppState.idle;
+
+  set appState(AppState newState) {
+    _appState = newState;
+    notifyListeners();
+  }
+
+  AppState get appState => _appState;
+}

lib/providers/user_provider.dart

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+import 'package:didvan/providers/core_provider.dart';
+
+class UserProvider extends CoreProvier {}