Remove variant for TrackState
Since we want to try having smaller MRs, I'm creating this one. This addresses the VariantTrackState
, which is dropped in favor of using FittableMeasurement
s. This allows access to the track parameters without going through a visitor, and limits the amount of code that needs to be aware of the type-erasure (it's just the GainMatrixUpdator
now).
Closes ACTS-558