Support Authorization Parameters with `request_uri`

[maennchen]

Spec: https://openid.net/specs/openid-connect-core-1_0.html#RequestUriParameter

Follow up of #232 & #239

Required for OpenID Connect Core: Dynamic Certification Profile Relying Party Tests certification

📌 This issue is here to track interest for the implementation. Leave a 👍 if you would like this implemented.