Problem Details: RFC7807 Deprecated in Favor of RFC9457

[travisgosselin]

RFC7807 is now replaced by RFC9457 which is backward compatible but includes other considerations that should be discussed and integrated. https://datatracker.ietf.org/doc/rfc9457/

Appendix D includes some of the key revisions:

 This revision has made the following changes:

   *  Section 4.2 introduces a registry of common problem type URIs

   *  Section 3 clarifies how multiple problems should be treated

   *  Section 3.1.1 provides guidance for using type URIs that cannot be
      dereferenced