Update of the shapes script

Hi Noel,

I've updated the shapes script to make it compatible with the new fake model naming (fakes_region). It seems to crash when running the data stuff (TES/noTES) but it makes sense since you probably stopped maintaining this comparison for the newest skim.
I also added a few 'features': category choice and output-format choice.

Minor: I added a latex label in the mva categories

Cheers,
Quentin

PS: the shapes script should probably be renamed 'plot-shapes' following the new convention