Set exception handler feature in developer exception page

[bjornen77]

When using the developer exception page, the exception handler
feature is now set before invoking the problem details service.
This makes it possible to get the original exception when using
the problem details service if wanted.

Fixes# #47060

[ghost]

Thanks for your PR, @bjornen77. Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[JamesNK]

This is ok, but have we considered adding the exception to the problem details context?

public class ProblemDetailsContext
{
    public Exception? Exception { get; init; }
}

When the problem details context is written from one of the exception handler middleware, the exception would be set on the context.

Getting the exception from a feature is a semi-advanced concept. Having it available on the problem details context would be more straightforward.

cc @captainsafia @mitchdenny @BrennanConroy @amcasey

[bjornen77]

I do not know if adding the exception to the context has been discussed, but I think it would be a good thing to do. Should we keep this change just to make the different exception handlers behave the same?

[captainsafia]

Getting the exception from a feature is a semi-advanced concept. Having it available on the problem details context would be more straightforward.

FWIW, I don't think getting it from the feature is that advanced. If anything, it has a bit of an edge over the ProblemDetailsContext since it relies on an API that's been around for longer. That being said, I'm not opposed to adding an Exception to the ProblemDetails.

Should we keep this change just to make the different exception handlers behave the same?

I think we should go with this change because adding the Exception to the ProblemDetails context would be additive. We should set the feature in the DEP even if it was set in the exception so it is accessible to people not using the ProblemDetailsService.

I do not know if adding the exception to the context has been discussed, but I think it would be a good thing to do.

Would you be interested in submitting an API proposal for this via the template?

[captainsafia]

LGTM given that I believe having the feature on the ProblemDetailsContext should happen in addition to this change.

[bjornen77]

Would you be interested in submitting an API proposal for this via the template?

Sure, no problem!