Score normalization pipeline needs some redesign

bob.bio.base implements a pipeline that does several types of score normalization in one shot:

• Z-Norm
• T-Norm
• S-Norm
• ZT-Norm
• Some variations of the adaptative norm.

Although logic (they are all variations of the same thing), this structure doesn't seem to scale to datasets where the number of comparisons explodes to millions of comparisons. I often face MemoryError issues that are super tough to track down (dask memory error).

Furthermore, the code is a bit convoluted. I think we need to break this down into small pieces.