Implementation of ATLAS_WCHARM_7TEV in the new format

[achiefa]

Re-implementation of the ATLAS_WJ_8TEV in the new commondata format.

$(x, Q^2)$ map and data-theory comparison

Legacy implementation: [default], [sys_10]
New implementation: [default]

[achiefa]

I have implemented the default variant for this dataset. See the description of the PR above for the $(x,Q^2)$ map and the data-theory comparison. The chi2's are unchanged between the two implementations.

RE the t0 matrices, they are the same between the new implementation and the legacy variant 😬

There is one thing that is still missing though. In the legacy implementaion, there is a sys_10 variant which accounts for two additional systematic uncertainties dubbed SCALEVAR. @enocera, @scarlehoff , do you know how to reconstruct these two additional sources?

[scarlehoff]

RE the t0 matrices, they are the same between the new implementation and the legacy variant 😬

Hooray!

There is one thing that is still missing though. In the legacy implementaion, there is a sys_10 variant which accounts for two additional systematic uncertainties dubbed SCALEVAR. @enocera, @scarlehoff , do you know how to reconstruct these two additional sources?

These are 3pt scale variations because we don't have NNLO corrections for this data.
Tbh, I would say these are obsolete in the new implementation since if we want to add theoretical uncertainties we should do it through a theory covmat, do you agree @enocera ?

Edit: actually, given that the legacy and the default agree 100%, I would say we can merge this as it is (I'll have a look at the rest of the implementation later). If we really want to use the _10 variant, we can do it with the ported one.

[achiefa]

@scarlehoff gotcha. Let's wait for the tests to finish then.

[enocera]

@achiefa Please forget about the sys_10 variant. This is indeed obsolete.

[scarlehoff]

I'll wait for #2226 to be merged and then I'll merge this.