Implement TxChannelRegistry for JIT Credentials

[nanderstabel]

Description

We need to add some sort of registry to the IssuanceState and potentially also VerificationState that can be used to open channels that can be triggered by specific DomainEvent's. The purpose of this registry is to enable channels to be opened from outside the core cqrs framework through which can be listened to specific events that are being dispatched.

One use case for this is for JIT credentials where when the /oid4vci/credential endpoint is called and the endpoint needs to wait for a JIT credential to arrive after it published the CredentialRequestVerified event. The endpoint opens a channel in the Repository and awaits for the CredentialsAdded event.

Motivation

This is a cleaner more efficient solution than our current polling solution described here: #70

Resources

• Use polling strategy instead of EXTERNAL_SERVER_RESPONSE_TIMEOUT_MS for JIT credentials #70

To-do List

• Add TxChannelRegistry

[M-Adam-Hus]

Implement TxChannelRegistry for JIT Credentials