Lwd-mixnet-proxy: light-wallet gRPC over the Nym mixnet, and what three days of measuring it found

[maxnym]

@Lowo88

We are happy to support turning that into something the SDK can run modules through. Joaco already said yes to writing the layer and bringing wire format as an issue on nymtech/nym first. From Nozy: we will keep producing independent client-half evidence (same gateway class, different machine) so any PR has a second measurement path, not only Joaco’s serving half.

I’m also happy to see a design doc / discuss it in here as well, instead of spreading discussion across multiple platforms.