A slightly-modified AuthenticatorAttestationResponse to simplify working with ArrayBuffers that are Base64URL-encoded in the browser so that they can be sent as JSON to the server.
https://w3c.github.io/webauthn/#dictdef-authenticatorattestationresponsejson
optional
authenticatorData: Base64URLString
optional
transports: AuthenticatorTransportFuture[]
optional
publicKeyAlgorithm: COSEAlgorithmIdentifier
optional
publicKey: Base64URLString