PWGLF: processMC for K0S-phi rapidity correlation studies (#6999)

* Set MC histos

* Accept MCevent

* Completed accepMCEvent

* V0DauMCTracks alias

* Added histos for GenMC

* Updated acceptEventQA and fill methods

* Added recoMC in processMCeff

* Added genMC in processMCeff

* New pion selection

* Updated Pi info filling

* Format fix

* Fix typo

Author: scannito