cover Rho_fixedGridRhoFastjetAll branch
This MR shall cover the branch that's been changed in Run 3.
I did test this PR locally with Run2 and Run3 samples. Though, test cases can be added to tests/test_jmesystcalc.py
but since the work on the correction-lib implementation is expected to be merged soon, it will no longer be required.
Edited by Oguz Guzel