Setup RFD900 to be able to send/receive serialized JSON data

[evinli]

We will be using the RFD900 telemetry radio to:

1. Send all our sensor data (gps, alt, heading) from the plane to the ground station
2. Send commands from the ground station BACK to the plane

For this task, you might have to read into the RFD900 docs here to setup the UART pins. You can also refer to our previous software here: https://github.com/ubcaerodesign/codex/blob/main/plane/peripherals/radio.py. As a deliverable, we will want the plane/peripherals/radio.py and ground/backend/radio.py implemented and tested with actual hardware.