Unreferenced examples

[c2bo]

As discussed in last DCP call, there are some examples in the examples folder of this repository that are currently not referenced in the spec.

This is the list of currently not referenced examples I found:

• credential_request_jwt_vc_json-ld.json
• credential_request_iso_mdl.json
• credential_offer_pre-authz_code.json
• credential_offer_sd_jwt_vc.json
• credential_request_jwt_vc_json.json

Should I create a PR removing these or are there some of these we want to reference in the spec / want them to stay in the repo?