Improve PAR failure error handling

[josephdecock]

When PAR fails, we aren't doing a great job of making it obvious that PAR is involved/the nature of the failure.

[alexanderjung-sdxag]

As additional information:
in CreateAuthorizeStateAsync when PushAuthorizationRequestAsync fails, the error information is supposedly copied to the state.
However, parResponse.Error does not contain the error information.
The information in parResponse.Raw / .Json containing the actual error information is lost.
AuthoritzationState has the generic error description set, but not error and IsError is false.

[bhazen]

@alexanderjung-sdxag I've been trying to reproduce this behavior today and have consistently been seeing the Error set. I've seen this with both AS returning a 400 or 500.

Do you recall the specifics of the scenario in which you were not seeing it set when you added your comment?