missing btag reshape uncertainties in flashggJetSystematics_cfi.py

[fabio-mon]

By default only the btag reshape uncertainties related to the JES are dumped in the output, while the purity and statistical uncertainties are not dumped (see [1] for the btag reshape uncertainties recommendations).

• the inclusion of the full set of btag uncertainties is straightforward [2]. This is already used in the resonant and non-resonant(HHcombination) HH->bbgg analyses but it was not propagated to the main flashgg branch.
• from [1]: "It should be noted that JES is not an uncertainty intrinsic to the shape calibration method. The JES-varied scale factors are only provided to propagate the effect of various JES sources to the central b-tag SF measurement."

[1] https://twiki.cern.ch/twiki/bin/viewauth/CMS/BTagShapeCalibration#Systematic_uncertainties
[2] fabio-mon@1f89c0a#diff-2bd0683a094a6649ac76f5e408715a0385a19da946214376abdec3de36a16f33