Description=Register a new device in the Trusted Device list. To use this method, the user should be logged.
Returns a [[TrustedDeviceChallenge]].
Returns a challenge code for pairing a a new or not-yet-enabled trusted device to the user account.
NOTE: The difference between this method and RegisterTrustedDeviceChallenge is that GetTrustedDeviceChallengeCode creates a challenge code for pairing to a trusted device that already exists. RegisterTrustedDeviceChallenge creates a challenge code for a device that is not associated to the user account yet.