isNonceChallenge
Returns true if response is a DPoP nonce challenge per RFC 9449 §8:
400 with body containing
error=use_dpop_nonce401 with a non-empty
DPoP-Nonceresponse header
Returns true if response is a DPoP nonce challenge per RFC 9449 §8:
400 with body containing error=use_dpop_nonce
401 with a non-empty DPoP-Nonce response header