Transmit data between robots over UWB

[antoinealb]

This pull request contains my (WIP) data transmission between the robots. Here are the main design ideas (see doc for reasoning):

• UWB boards receive message from UAVCAN/UWB and sends them over UWB/UAVCAN without processing.
• The master firmware contains a higher level protocol, namely UDP/IP.

Steps needed:

• [x] Implement UAVCAN -> UWB path
• [x] Implement UWB -> UAVCAN path
• [x] Test on hardware
• [ ] Implement lwip interface that uses UAVCAN for sending out frames
• [x] Implement network adapter for IP <-> UAVCAN (works on macOS so far)

I think the two last points belong in a different, later PR.

[SyrianSpock]

Happy to see progress on this :+1:

[antoinealb]

Results of tonight testing:

• UWB <-> CAN works well
• IP over UAVCAN/UWB works surprisingly well I would say, with pings in the 40 ms range, we even got TCP working(!).
• The python IP <-> CAN adapter does not work under Linux, the TAP interface setup is different.

I think this PR is ready for review, the Linux port of the IP script, as well as the lwip interface can be added later.

Please also note that if the UDP/IP design is not of your taste, most of this code (except the Python script) can be used independently of whatever protocol we choose to use on top of the UWB data packets.