Loading a saved Comparer/ComparerCollection restores raw-model-data as PointObservation

[jsmariegaard]

The problem seems to be this line:

modelskill/modelskill/comparison/_comparison.py

Line 1307 in ba82071

ts = PointObservation(data=ds, name=new_key)

inside the load() method

[jsmariegaard]

Would be good to fix prior to releasing the new feature in #493