Convert LEDs to I2C

[dburnsii]

With looking at multiple boards, and considering some of the issues seen with custom protocols regarding timing, all devices that communicate with the main board should be communicating with I2C.

For the LEDs, this will likely mean creating a custom firmware on an MCU, likely an Arduino. This will differ from the old design in that it will use protocol closer to how the pixels actually work, and it will be over I2C instead of UART over USB.