Add attachments in the presentation request

[cre8]

The Verifier Attestation JWT is good for authentication, but limited in further usage. Current requirements from the Implementing Acts require that the Relying Party need to present a so called Registration Certificate, where the intended use is attested by the Wallet-Relying Party Registrar. To avoid requests from the wallet to the registrar, the Relying Party should be able to attach this certificate to the presentation request.

The request includes a new credentials attribute, that allows to attach
certificates like registration and authorization certificates.

• type: STRING, media type of the attached credential, helping to parse the credential by the Wallet. The value has to be registered in the IANA media types registry.
• data: ANY, content of the credential. Will be parsed by the Wallet based on the type.
• credentialsMatch: STRING[], when the provided certificate is used for authorization, it will list the credential ids from the dcql_query.

{
  "x5c": [],
  "typ": "JWT",
  "alg": "ES256"
}
.
{
  "response_type":"vp_token",
  "client_id":"x509_san_dns:client.example.org",
  "response_mode":"direct_post",
  "dcql_query":{
    "credentials":[
      {
        "id":"my_credential",
        "format":"vc+sd-jwt",
        "meta":{
          "vct_values":[
            "https://credentials.example.com/identity_credential"
          ]
        },
        "claims":[
          {
            "path":[
              "last_name"
            ]
          },
          {
            "path":[
              "first_name"
            ]
          },
          {
            "path":[
              "address",
              "street_address"
            ]
          }
        ]
      }
    ]
  },
  "credentials":[
    {
      "type:" "jose",
      "data": "base64-encoded-registrationCertificate-jws"
    },
    {
      "type:" "jose",
      "data": "base64-encoded-authorizationCertificate-jws",
      "credentialsMatch": ["my_credential"]
    }
  ]
}