feature(training): Добавлен состояния загрузки, пустоты и наличие данных на экране тренировки

lib/screens/training/states/loading.dart

@@ -0,0 +1,35 @@
+import 'package:auto_route/auto_route.dart';
+import 'package:flutter/material.dart';
+import 'package:remever/common/resources.dart';
+import 'package:remever/common/widgets/typography.dart';
+
+class TrainingLoading extends StatelessWidget {
+  const TrainingLoading({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      backgroundColor: AppColors.bg,
+      appBar: _buildAppBar(context),
+      body: Center(child: CircularProgressIndicator(color: AppColors.primary)),
+    );
+  }
+
+  /// Построение шапки
+  AppBar _buildAppBar(BuildContext context) {
+    return AppBar(
+      backgroundColor: AppColors.white,
+      shadowColor: Colors.transparent,
+      leading: GestureDetector(
+        onTap: () => context.back(),
+        child: const Icon(Icons.close, color: Colors.black),
+      ),
+      centerTitle: true,
+      title: AppTypography(
+        'Тренировка',
+        type: SemiBold20px(),
+        color: AppColors.body_text,
+      ),
+    );
+  }
+}