AuthorizationCredential: rename "issuerDIDDoc"?

[llorllale]

ConsentCredential was renamed to AuthorizationCredential to align with UMA (ref: trustbloc/adapter#188).

userDID was renamed to subjectDID to be "more generic" (ref: PR #20 (comment)). I would further this with the fact that the subject of a set of claims is not necessarily the same party that authorized access to said claims (ref: #23 ).

This puts us squarely in authZ land with the resource owner decoupled from the party (human, institution, machine...) that is driving the client requesting access to the resources. AKA User-Managed Access.

In UMA, the resource owner controls (accept/reject) whether the authorization server issues a requesting party token to the requesting party. We are essentially doing the same, but relaying the RPT to the requesting party via the resource owner's wallet.

There is no "issuer" role in UMA. What there is though is "resource server". Or more generically it's the location of the resource, similar to locations in RAR.

Should we rename "issuerDIDDoc" to "location"? location falls outside of UMA but I feel it captures the meaning behind this claim quite well.