toRelyingPartyValidator

The RelyingPartyValidator establishing the trust these sources established, to migrate from relyingPartyTrust: RelyingPartyTrust.Certificates become the anchors of the access certificate providers, also if there are none, so that configured trust stays required; RelyingPartyTrust.PreRegisteredClients and the verifier attester sources map to theirs. RelyingPartyTrust.Custom no longer takes effect, as it decides opaquely instead of returning the keys of the relying party, see ClientIdentifierTrust.