Init core module

core/lib/presentation/state/success.dart

@@ -0,0 +1,15 @@
+import 'package:equatable/equatable.dart';
+
+abstract class Success with EquatableMixin {}
+
+abstract class ViewState extends Success {}
+
+class UIState extends ViewState {
+  static final idle = UIState();
+  static final loading = UIState();
+
+  UIState() : super();
+
+  @override
+  List<Object?> get props => [];
+}