TF-2613 Add validate same domain method & unit test

Signed-off-by: dab246 <tdvu@linagora.com>

test/features/email/email_address_is_same_domain_test.dart

@@ -0,0 +1,33 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:tmail_ui_user/features/email/presentation/utils/email_utils.dart';
+
+void main() {
+  group('EmailUtils', () {
+    test('isSameDomain should return true when email is from the same domain as server', () {
+      String emailAddress = 'user@example.com';
+      String serverDomain = 'example.com';
+
+      bool result = EmailUtils.isSameDomain(emailAddress: emailAddress, serverDomain: serverDomain);
+
+      expect(result, true);
+    });
+
+    test('isSameDomain should return false when email is not from the same domain as server', () {
+      String emailAddress = 'user@example.com';
+      String serverDomain = 'example2.com';
+
+      bool result = EmailUtils.isSameDomain(emailAddress: emailAddress, serverDomain: serverDomain);
+
+      expect(result, false);
+    });
+
+    test('isSameDomain should return false when email is invalid', () {
+      String emailAddress = 'invalid_email';
+      String serverDomain = 'example.com';
+
+      bool result = EmailUtils.isSameDomain(emailAddress: emailAddress, serverDomain: serverDomain);
+
+      expect(result, false);
+    });
+  });
+}