[OpenID4VCI] credentials_supported

[peppelinux]

According to https://github.com/openid/OpenID4VCI/pull/86#issuecomment-1777155395

the structure of credentials_supported is going to change, please provide your position for that

[peppelinux]

here an example about how it would be right now

    "credentials_supported": {
        "UniversityDegreeCredential": {
            "format": "jwt_vc_json",
            "scope": "UniversityDegree",
            "cryptographic_binding_methods_supported": [
                "did:example"
            ],
            "cryptographic_suites_supported": [
                "ES256K"
            ],
            "credential_definition":{
                "type": [
                    "VerifiableCredential",
                    "UniversityDegreeCredential"
                ],
                "credentialSubject": {
                    "given_name": {
                        "display": [
                            {
                                "name": "Given Name",
                                "locale": "en-US"
                            }
                        ]
                    },
                    "family_name": {
                        "display": [
                            {
                                "name": "Surname",
                                "locale": "en-US"
                            }
                        ]
                    },
                    "degree": {},
                    "gpa": {
                        "display": [
                            {
                                "name": "GPA"
                            }
                        ]
                    }
                }
            },
            "proof_types_supported": [
                "jwt"
            ],
            "display": [
                {
                    "name": "University Credential",
                    "locale": "en-US",
                    "logo": {
                        "url": "https://exampleuniversity.com/public/logo.png",
                        "alt_text": "a square logo of a university"
                    },
                    "background_color": "#12107c",
                    "text_color": "#FFFFFF"
                }
            ]
        }
    }