Add upgrade test which runs over a big event

@raaij observed that in the debug build the assert here is triggered. The problem is that when resizing a vector in the PrPixelTracking, the keys of all tracks are lost.

The test runs over this event (Event 100 in the digi file). Probably better would be to filter some high occupancy events and put them in here (Anyone has a script to do that?).

The solution of the problem is being discussed in Rec#24 (closed).