Support for OpenID Connect Dynamic Client Registration

[azmeuk]

Authlib implements RFC7591 that allow for dynamic client registration as defined in the OAuth2 spec.
However, the OpenID Connect Dynamic Client Registration specification details some additional claims that are currently ignored by the RFC7591 implementation:

• token_endpoint_auth_signing_alg
• application_type
• sector_identifier_uri
• subject_type
• id_token_signed_response_alg
• id_token_encrypted_response_alg
• id_token_encrypted_response_enc
• userinfo_signed_response_alg
• userinfo_encrypted_response_alg
• userinfo_encrypted_response_enc
• default_max_age
• require_auth_time
• default_acr_values
• initiate_login_uri
• request_object_signing_alg
• request_object_encryption_alg
• request_object_encryption_enc
• request_uris

The OpenID Connect certification test suite attempts to register some of those parameters.

Note that some other specs like OpenID Connect RP-Initiated Logout add their own claims like post_logout_redirect_uris. #500