Review uses of challenge and domain and ensure those terms are used for VerifiablePresentaitons

[aljones15]

While the terms challenge and domain can be used on a VC, their intended use is for Verifiable Presentations.
The schema for the reponse from credentials/issue still contains a VC with domain and challenge in it.
The API in general needs a once over ensuring that challenge and domain are used in the context of VerifiablePresentations.

[msporny]

The group discussed this on the 2024-07-23 telecon:

@dlongley noted that the specification is currently incorrect by allowing domain and challenge to be used on a VC (it should not allow that). domain and challenge must only be used on a presentation.

A PR should be raised to create two JSON schemas for the proof field -- one that is used on VCs and one that is used on VPs. The domain and challenge properties must only be used on proofs that are found on VPs.

[TallTed]

Issue title needs typo correction, from VerifiablePresentaitons to VerifiablePresentations.