If there's an error on a participant shard that added txn participants, we should attach additionalParticipants to the response so that:
1. Mongos won't retry even if the error was a retriable error on a first txn statement.
2. Mongos can abort the transaction on the added participants (note this isn't strictly necessary, because the transaction will abort either after TransactionLifetimeLimitSeconds or when it receives a new txn request with a higher txn number)