Advanced demo for the GPCA-UI.

Users can interact with the following buttons:
* On/Off: used to turn on/off the pump
* Arrow keys: used to set the volume to be infused
* Ok: used to confirm the volume to be infused
* Start: used to start an infusion
* Stop: used to stop an infusion

Periodic events are used to send initialisation commands to the state controller and to simulate infusion progress.