[Federation] request_parameter_supported

Issue #1523 resolved
Takahiko Kawasaki created an issue

The configuration of op.umu.se in A.2.8 of OpenID Connect Federation 1.0 says that request_parameter_supported is false, but the authentication request in A.3.1 is using the request parameter.

The configuration of op.umu.se should say that request_parameter_supported is true.

In addition, because the default value of request_parameter_supported is false (OIDC Discovery Section 3), the configuration of op.umu.se shown in A.2.1 should explicitly include "request_parameter_supported":true.