Signal holder app when a transaction is done

[cvarjao]

In the scenario where a holder scans a QR code and an issuer needs a sequence of proof request(s) and/or credential offer(s), the holder app needs a signal to know when the transaction is done so that it can stop waiting, and more importantly resume the process to the caller agent (might be another mobile app)

goal code might be helpful to indicate the purpose of scanning a QR Code, but we might need some other message to indicate "done".

Related Issues

• Send multiple credential offers to holder on single connection (one QR code) openwallet-foundation/bifold-wallet#803