[PWGCF] jEPFlowAnalysis.cxx: fix bug and add qa

[jikim1290]

fix bug for the event selection
add qa plots
add rct selection

[github-actions]

O2 linter results: ❌ 0 errors, ⚠️ 3 warnings, 🔕 0 disabled

[vkucera]

Fix the bugs.

PWGCF/JCorran/Tasks/jEPFlowAnalysis.cxx

PWGCF/JCorran/Tasks/jEPFlowAnalysis.cxx:167:7: warning: Member variable 'JEPFlowAnalysis::detId' has no initializer. [uninitMemberVarNoCtor]
PWGCF/JCorran/Tasks/jEPFlowAnalysis.cxx:168:7: warning: Member variable 'JEPFlowAnalysis::refAId' has no initializer. [uninitMemberVarNoCtor]
PWGCF/JCorran/Tasks/jEPFlowAnalysis.cxx:169:7: warning: Member variable 'JEPFlowAnalysis::refBId' has no initializer. [uninitMemberVarNoCtor]
PWGCF/JCorran/Tasks/jEPFlowAnalysis.cxx:170:7: warning: Member variable 'JEPFlowAnalysis::harmInd' has no initializer. [uninitMemberVarNoCtor]
PWGCF/JCorran/Tasks/jEPFlowAnalysis.cxx:175:9: warning: Member variable 'JEPFlowAnalysis::cent' has no initializer. [uninitMemberVarNoCtor]
PWGCF/JCorran/Tasks/jEPFlowAnalysis.cxx:179:9: warning: Member variable 'JEPFlowAnalysis::q2Mag' has no initializer. [uninitMemberVarNoCtor]
PWGCF/JCorran/Tasks/jEPFlowAnalysis.cxx:181:9: warning: Member variable 'JEPFlowAnalysis::activity' has no initializer. [uninitMemberVarNoCtor]
PWGCF/JCorran/Tasks/jEPFlowAnalysis.cxx:182:9: warning: Member variable 'JEPFlowAnalysis::qOvecM' has no initializer. [uninitMemberVarNoCtor]
PWGCF/JCorran/Tasks/jEPFlowAnalysis.cxx:183:9: warning: Member variable 'JEPFlowAnalysis::highestPt' has no initializer. [uninitMemberVarNoCtor]
PWGCF/JCorran/Tasks/jEPFlowAnalysis.cxx:184:9: warning: Member variable 'JEPFlowAnalysis::hPtPhi' has no initializer. [uninitMemberVarNoCtor]
PWGCF/JCorran/Tasks/jEPFlowAnalysis.cxx:686:11: style: Local variable 'cent' shadows outer member [shadowMember]
PWGCF/JCorran/Tasks/jEPFlowAnalysis.cxx:727:11: style: Local variable 'cent' shadows outer member [shadowMember]