Add domain layer for get Session

lib/features/session/domain/repository/session_repository.dart

@@ -0,0 +1,5 @@
+import 'package:jmap_dart_client/jmap/core/session/session.dart';
+
+abstract class SessionRepository {
+  Future<Session> getSession();
+}

lib/features/session/domain/state/get_session_state.dart

@@ -0,0 +1,20 @@
+import 'package:core/core.dart';
+import 'package:jmap_dart_client/jmap/core/session/session.dart';
+
+class GetSessionSuccess extends UIState {
+  final Session session;
+
+  GetSessionSuccess(this.session);
+
+  @override
+  List<Object> get props => [session];
+}
+
+class GetSessionFailure extends FeatureFailure {
+  final exception;
+
+  GetSessionFailure(this.exception);
+
+  @override
+  List<Object> get props => [exception];
+}

lib/features/session/domain/usecases/get_session_interactor.dart

@@ -0,0 +1,19 @@
+import 'package:core/core.dart';
+import 'package:dartz/dartz.dart';
+import 'package:tmail_ui_user/features/session/domain/repository/session_repository.dart';
+import 'package:tmail_ui_user/features/session/domain/state/get_session_state.dart';
+
+class GetSessionInteractor {
+  final SessionRepository sessionRepository;
+
+  GetSessionInteractor(this.sessionRepository);
+
+  Future<Either<Failure, Success>> execute() async {
+    try {
+      final session = await sessionRepository.getSession();
+      return Right<Failure, Success>(GetSessionSuccess(session));
+    } catch (e) {
+      return Left<Failure, Success>(GetSessionFailure(e));
+    }
+  }
+}