Presentation of non-mdoc credentials (e.g. sd-jwt vc) offline

[tlodderstedt]

We had a good discussion at IIW #39 about ways to enable offline presentation of non-mdoc credentials.
Options discussed:

• Extension of ISO 18013-5
• Pursue OID4VP over BLE
• Use CTAP/HYBRID as transport for OID4VP requests and responses.
  The consensus in the session was the CTAP/HYBRID seems to be the most attractive approach as it leveraged CTAP/HYBRID (implementations and community and roadmap) and also leverages OID4VP feature for offline (e.g. transaction data).

Note: CTAP/HYBRID sends the data over the internet (via a relay server). Plan is to extend it with BLE and UWB. That would enable real offline presentation.

What we actually need is an appendix in OID4VP describing how CTAP could be used to pass OID4VP requests and receive respective responses. It should then work with all transports (even UWB going forward).