Optical Input (i.e. flicker code)

This method uses a so-called "challenge" which is chiefly a row of digits which are encoded in a flicker graphic which is then read by a specific card reader device which is held to the monitor to read that code. The possible contents of the methodParams are:

- char challenge: Hex code in ASCII form with a row of bytes to be converted to a flicker code (e.g. "123456789ABC"
- char methodName: Name of the method (optional)
- char methodDescription: Description of the method (optional)