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

lib/screens/training/cubit/training_cubit.dart

@@ -0,0 +1,25 @@
+import 'package:bloc/bloc.dart';
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+part 'training_state.dart';
+part 'training_cubit.freezed.dart';
+
+class TrainingCubit extends Cubit<TrainingState> {
+  TrainingCubit() : super(TrainingState.data());
+
+  Future<void> toLoading() async {
+    emit(TrainingState.loading());
+  }
+
+  Future<void> toEmptyState() async {
+    emit(TrainingState.empty());
+  }
+
+  Future<void> toDataState() async {
+    emit(TrainingState.data());
+  }
+
+  Future<void> toResultState() async {
+    emit(TrainingState.result());
+  }
+}