Draft: Add vertex constraints to DecayTreeFitterAlg
- Pass mass constraint by string. Addresses https://gitlab.cern.ch/lhcb-dpa/project/-/issues/175 . This is now !1030 (merged).
- Constrain to PV : https://gitlab.cern.ch/lhcb-dpa/project/-/issues/172
Needs a DaVinci test.
Edited by Patrick Koppenburg