Replace plotoptions commondata functionality with commondataparser

[Zaharid]

I am towing around with the commondata parser and it is so much nicer than the older interface. For example in that it keeps the cuts info. Would be great to have it used in places like

nnpdf/validphys2/src/validphys/plotoptions/core.py

Line 309 in 5fe81ab

table = pd.DataFrame(data.get_kintable(), columns=default_labels[1:])

(and that whole subpackage really) and propagated properly to the relevant parts of dataplots.py (which might allow to clean up the code of plot_fancy, which is anything but).

[RosalynLP]

@Zaharid So here are we talking about actually using the new CommonData python objects and then using something like data.systype_table() here? Or do you mean just use the parse_commondata action? In which case I'm not entirely sure what you have in mind - could you please clarify/give an example?

[Zaharid]

The former. Basically never call commondata.load in the module and use the python stuff instead. That would likely spill to plot_fancy and some other places, which would help simplifying them; dealing with cuts is a big annoyance in there.

[scarlehoff]

Done in #1678