Multiple tracks can share the same hit

[ftouchte]

https://github.com/ftouchte/coatjava/blob/f2b5ec01912ef42ab2d631581d332d1f5e66d690/reconstruction/alert/src/main/java/org/jlab/rec/ahdc/KalmanFilter/KalmanFilter.java#L105C1-L105C34

In that sense, in the relevant AHDC::hits entry (a given column), the trackId will be the one the last track containing this hit in the for loop. For example, if the track t1 and t2 share the hit h9 with t1 < t2, the trackId of the h9 will be t1.