Make device IDs based on MAC addresses

[tcsullivan]

We're leaning towards having device IDs be generated from the device's MAC address, meaning a physical device will always have the same ID. The server can coordinate the linking of IDs to users.

The UUID library we're using can be seeded so that its generation isn't truly random. At that point, we may not need to bother with storing the UUID in "EEPROM" either.

Maybe the UUID format is not even necessary? Is it bad to expose our MAC addresses? Might want some input from cybersecurity people on this...

[tcsullivan]

We could generate our own IDs and permanently store them in eFuse memory. Would just need a tool/script to generate new IDs and make sure they are always unique.

[tcsullivan]

I've made the device ID a UUID generated from the device's MAC address which should be okay to start with. Still need to confirm if we should burn custom IDs instead.