Add credential format specific sections for IAR endpoint binding in VPs.

Is it clear enough that Credential Formats correspond to the requested Credential in the IAR, and not to the requested Credential in the VCI request?

I did not update the audience in the VP, but propose a fix in £629
al here fix: just do derived origin binding #629

fixes #590
fixes #620

(changes by Oliver, moved from the 1.0 to 1.1 spec by Joseph)

Author: jogu