[WIP] Implement RF-Score v4

[mwojcikowski]

We are still missing docking phase (Vina) during generation of initial descriptors.

RF-Score v4 needs docked conformers. We need to add additional transformer functionality to a scorer method. Eventually we want to split _gen_pdbbind_desc to following methods:

1. supply molecules/conformers
2. transform input molecules (optionally, docking, some noise, etc)
3. generate the descriptors