Add virtual display functionality #88
Description
For now have the ability for the web UI to show the LCD1602 display output if enabled on the device, so create a new display driver for virtual 1602, but have it load if the physical one is loaded. Display abstraction will deal with the rest providing the same methods are implemented in the virtual driver. Later I will add the option to have additional virtual displays to allow the web UI to receive display data as if a display was connected when it isn't.
Display driver will need to use some kind of websocket type communication from the SMIBHID back to the web client for realtime push.