Start writing the web app

Signed-off-by: Nikolai Rodionov <allanger@posteo.com>

lib/features/test/application/test_controller.dart

@@ -0,0 +1,28 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:softplayer_web/core/api/v1/test.dart';
+import 'package:softplayer_web/core/tokens/application/tokens_application.dart';
+
+final pingControllerProvider = AsyncNotifierProvider<PingController, String>(
+  PingController.new,
+);
+
+class PingController extends AsyncNotifier<String> {
+  @override
+  Future<String> build() async {
+    return 'Idle';
+  }
+
+  Future<void> ping() async {
+    state = const AsyncLoading();
+
+    state = await AsyncValue.guard(() async {
+      final testGrpc = ref.read(testGrpcProvider);
+      final tokenCtrl = ref.read(tokensControllerProvider.notifier);
+      await tokenCtrl.checkTokens();
+
+      await testGrpc.pong();
+
+      return 'Ping successful';
+    });
+  }
+}