GetProbs in different modules

Hi @vagudets,

I'm working on the computation of probabilities and testing the new features developed by @nperez in dev_probs to handle absolute thresholds.

I've noticed that we have two versions of the GetProbs.R function one in the Skill module and another in the Crossval module. I think this is not a major issue, but it could potentially cause some confusion.

It would be great if we could use the most recent version of the function (i.e., the one in Crossval) across the different modules.

Thanks a lot,

Vero