Adding the track building for the muon trigger in the new JO test (ATR-20388):
- cloned the offline flags to set muon trigger specific values, and added the track builder as part of the muon trigger reco sequence
- migrated the tools in the muon seeded segment finder to be private
- removed a few instances of 'addPublicTool' where we can use private tools
- note that the region selector service used by the segment recovery is currently the default (which is correct at the moment), but this will probably need to be changed in the future, so keeping the property commented out for now.