Complete verification links and preserve verified login email (#60)

frontend/packages/sxchnge_auth/lib/src/dto/results.dart

@@ -6,6 +6,7 @@ class AuthDTO {
 }
 
 class VerificationDTO {
-  const VerificationDTO({required this.simulated});
+  const VerificationDTO({required this.simulated, this.email});
   final bool simulated;
+  final String? email;
 }