Implement coordinate hit and run sampler

[stelmo]

The current state of the art sampler is CCHR (https://academic.oup.com/bioinformatics/article/33/11/1741/2964731). We should implement this. A side goal would be to add some sort of GPU functionality, but most users won't have a gpu, so I would put gpu stuff as secondary importance.

[exaexa]

Can we move this to the CuFluxSampler repo?

[stelmo]

100% please move this

[exaexa]

The other question is if (how much) the coordinate methods are viable for GPUs. Might be nice to have approximate coordinate computation (lanczos-style) because just SVDing everything won't be of much help.