How to link a message to a context? (aka "threading")

[llorllale]

(sprung from this comment)

DIDComm v1 standardized the threading decorator and the semantics around it.

I understand the DIDComm JWM profile envelope is the place where this context should be established.

AFAICT, there is no standard way to link an out-of-band invitation to a subsequent message without this.

[TelegramSam]

We have a thread_id provided by JWM as you pointed out. Adding the parent thread would be an excellent mechanism for context association. I know of no conflict in doing so, and it should be an easy PR.

[llorllale]

@TelegramSam I don't see thread_id in the DIDComm JWM Profile although it exists in the I-D. I assume it needs to be added to the DIDComm profile.

[llorllale]

Submitted PR #102