Update Yadism theory cards.

[giacomomagni]

The parsing of the new nnpdf theory cards is not compliant with yadism anymore.

In particular :

1. Here we need to allow for floats:
   

   yadism/src/yadism/coefficient_functions/coupling_constants.py

   Lines 418 to 420 in 181b28b

   	"CKM": CKM2Matrix.from_str(
   	theory["CKM"]
   	), # TODO remove default in PDG2020 Eq. 12.33

2. The kyes RenScaleVar, FactScaleVar are no longer supported, so we should consider to drop them here.
   I suggest to include scale variations as default and eventually allow the possibility of skipping them.
   In particular as grids do not depends on XIR and XIF it's more convenient to have them also for the central theories.

3. This line

   yadism/src/yadism/input/compatibility.py

   Line 143 in 181b28b

   if "PTODIS" not in theory:

has to be modified to:

if "PTODIS" not in theory or theory["PTODIS"] is None: