Add demo to open Bambu X1 Carbon live stream

[jamwaffles]

This needs more work to integrate it into the server (e.g. providing a WebRTC endpoint, dynamic IP and access code), but as it stands it's now possible to get video frames from the printer.

This has been a huge pain in the arse because there isn't a good RTSP auth crate that I could find, so that was written from scratch. Additionally, the network data that comes out of the printer starts with this weird 0x2400(len low)(len high) 4 byte preamble that I couldn't find in any specs anywhere, so that confused me for days as it meant none of the H.264 decoders I tried would pick up a frame.

I'm sick of reading hex off the command line so I'll present this code as-is for someone else (maybe me later lol) to integrate into machine-api proper.

I've left my NOTES.md in as it might prove helpful in the future, but be aware the file is pretty much a live stream (hah)/dumping ground of things I found in my travels.

Makes steps towards closing #52

[jessfraz]

THIS IS AWESOME!

[jamwaffles]

Closing in favour of #128 which uses a branch not in my fork.