Python3 CSI decoding and plotting

[zeroby0]

Hi!

This PR enables decoding and plotting CSI samples for bcm43455c0 and bcm4339 chips. Support for other chips and formats could be added easily, and I'm looking for help with that.

You can look at the usage and documentation here: https://github.com/nexmonster/nexmon_csi/tree/feature/python/utils/python

The actual code and the updates to the Readme are in separate commits, so you can chose to merge only the code, and update the Readme in a way you prefer.

I had help from @Gi-z and @tweigel-dev, and took design inspiration from their projects of similar nature.

[matthiasseemoo]

Nice tool. If you are maintaining the code in your own repository, I would rather reference your repository instead of merging the changes.

[NewbCooder]

Hi @zeroby0 this looks great. If you are still looking for support for chips I could help you with bcm4366 (Asus RT-AC86U) as I have been working on it for a while. Let me know if you want to collaborate!

[zeroby0]

Heyo @NewbCooder

I appreciate the offer a lot! I've forgotten to update here, but I've written a decoder for bcm4366 and it's available in https://github.com/nexmonster/nexcsi

The code is still immature and incomplete imo, but i have some initial decoding going on there. I'm working on a different project right now, but I expect to get back to working on nexmon related tools soon and I'll call upon you for help then :)

I've noticed you participating in the issues and helping out people, thank you for that. Nexmon_* is still hard to use for beginners, so any help makes a big difference.