TF-3826 Try guessing webfinger when dns look up fail

lib/features/login/domain/model/oidc_guessing_origin.dart

@@ -0,0 +1,24 @@
+import 'package:tmail_ui_user/features/email/presentation/utils/email_utils.dart';
+
+enum OidcGuessingOrigin {
+  empty(origin: ''),
+  autoDiscover(origin: 'autodiscover'),
+  jmap(origin: 'jmap');
+
+  const OidcGuessingOrigin({required this.origin});
+
+  final String origin;
+
+  String url(String email) {
+    if (!EmailUtils.isEmailAddressValid(email)) {
+      throw ArgumentError('Invalid email address: $email');
+    }
+    final emailDomain = email.split('@').last;
+    return switch (this) {
+      OidcGuessingOrigin.empty => 'https://$emailDomain',
+      _ => origin.trim().isEmpty
+        ? OidcGuessingOrigin.empty.url(email)
+        : 'https://$origin.$emailDomain',
+    };
+  }
+}