Don't assume the Arduino is at `/dev/ttyAMA0`

[jonapap]

ArduinoProxy.cpp always assumes that the Arduino will be found at /dev/ttyAMA0. Thing is, this is will not always be the case. We should make that part of the code a bit more robust and search through all available serial ports. Probably there is some form of ID we can use to confirm this is the Arduino. We'll have to research this.

[ajayyy]

We can define this in config.h and control it via environment variable

[ajayyy]

This now changes automatically on desktop

[ajayyy]

Keeping open since it is still hard coded