Roland Hedberg

### All Submissions: * [X] Have you checked to ensure there aren't other open [Pull Requests](../../pulls) for the same update/change? * [X] Have you added an explanation of what problem...

Extensions in documentation

1

We need to enumerate what extensions (RFC, I-D or OIDF spec based) that we have in the code base and how they can be used.

The dump/load methods used for persistence storage of state was not working well in the general case. This PR fixes that

Response type handling

2

Updated to align with the official PAR RFC. Enforce that an access code can only be used once. Worked with handling client_id. Added upstream_get to UserInfo classes. Improved resilience. Entity...