All random generation should be settable with numpy random generator

[paucodeici]

I am not aware of where exactly there are call to numpy.random but it should be call to some random number generator fed in the function.

Typically pointpats.random.poisson( rng=np.random.default_rng(???)) or specify a seed or something

Can do the change but I am not aware if it would break anything or would be long and painful change.