Support for Demonstrating Proof of Possession (DPoP) authorization tokens

### 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.

_No response_

### Describe the solution you'd like

[Demonstrating Proof of Possession (DPoP) RFC 9449](https://datatracker.ietf.org/doc/html/rfc9449) is a new addition to the OAuth 2.0 framework. It makes it possible for clients to prove that the access token being used actually belongs to the client and not to an attacker. Several identity providers have already implemented DPoP support:

Duende: https://blog.duendesoftware.com/posts/20230504_dpop/
Curity: https://curity.io/resources/learn/dpop-overview/
Okta: https://www.okta.com/blog/2023/06/a-leap-forward-in-token-security-okta-adds-support-for-dpop/

The current option in .NET is to either use Duende libraries, or write your own DPoP-implementation on top of the existing authentication stack in aspnetcore. It would be great if this was a capability that would come together with aspnetcore as DPoP is being more adopted by OAuth applications.

### Additional context

_No response_