Using isCharged function for pFlow objects
@mhodgkin reported in ATLJETMET-796 that the charge of the pFlow object is compared to != 0.0. To avoid issues due to numerical precision, the isCharged function is now used everywhere and 1e-6 is used instead of FLT_MIN as discussed in the above mentioned JIRA ticket. The same changes were already merged in rel21.2: 27737
Also tagging @wbalunas, @williams and @khoo for their information.