closes #45774

Instead of using low level Http requests, this PR adds support for OID4VCI requests using the well known OAuthClient request/response pattern like this ...

Rich AuthorizationRequest with AuthorizationDetails

This PR also adds support for ClientMetadata in the AuthorizationRequest

        AuthorizationRequest authRequest = new AuthorizationRequestBuilder()
                .withClientId(issClientId)
                .withAuthorizationDetail(authDetail)
                .withRedirectUri(redirectUri)
                .withCodeChallenge(pkce)
                .build();

        AuthorizationRequestResponse authResponse = new AuthorizationRequestRequest(oauth, authRequest)
                .credentials(ctx.targetUser, "password")
                .send();

If removes OID4VCAuthorizationDetailResponse in favor of OID4VCAuthorizationDetail with credential_identifiers (i.e. it should not be necessary to distinguish between the two)

Response status code checking is already done in the response base classes - I unified the error response handling like this, so that clients won't have to deal with it every time as part of a request.

    public CredentialResponse getCredentialResponse() {
        return Optional.ofNullable(credentialResponse).orElseThrow(() ->
                new IllegalStateException(String.format("[%s] %s", getError(), getErrorDescription())));
    }

AbstractHttpPostRequest now supports ...

• arbitrary payloads (i.e. not just url-form-encoded)
• bearer token authentication

Oid4vcCredentialRequest can extend it directly.