Add support for decay descriptor arrows
Support for -->
, =>
, ==>
. See https://gitlab.cern.ch/lhcb/Rec/-/blob/master/Phys/DaVinciKernel/src/component/DecayFinder.cpp?ref_type=heads#L161
Support for -->
, =>
, ==>
. See https://gitlab.cern.ch/lhcb/Rec/-/blob/master/Phys/DaVinciKernel/src/component/DecayFinder.cpp?ref_type=heads#L161