Move ProblemDetails outside of Asp.Net Core

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Is your feature request related to a problem? Please describe the problem.

When creating a C# client library for an API which uses ProblemDetails currently the best solution I can find is to include a FrameworkReference to Asp.NetCore in that client library.

Of course you can generate or hand write a ProblemDetails class for the client project but it gets tedious with inheritence for custom problem details.

### Describe the solution you'd like

I would like ProblemDetails to be available outside of asp.net core. Maybe somewhere near HttpClient or somewhere in the BCL? Or a NuGet package (possibly not as I understand the asp.net project would not like to have NuGet dependencies)?

### Additional context

_No response_