Add QSR

Created by: PhilipVinc

Closes #556 (closed)

cc @nkaeming, that's for you. If you get it to the end merge line I'll offer you a beer.

this is my draft implementation.It already works fairly well but the two things to investigate are 1) setup (right now it does a lot of preprocessing, but this might not be the smartest way to go) and 2) API.

Also, code is written use jax's mask api which is unstable and will be soon removed in favour of something else. Also it's a bad choice because masking does not diminish computing time. So maybe the core of the algorithm could be written better.

Code should also be double-checked and tests written...

There's an example that should work.