Added debug information to CKF2::finalize

Write out number of events, seeds, fitted tracks and good re-fitted tracks in CKF2::finalize.

Tracking/Acts/FaserActsKalmanFilter/FaserActsKalmanFilter/CKF2.h

@@ -111,6 +111,11 @@ public:
   virtual Acts::MagneticFieldContext getMagneticFieldContext(const EventContext& ctx) const;
 
 private:
+  size_t m_numberOfEvents {0};
+  size_t m_numberOfTrackSeeds {0};
+  size_t m_numberOfFittedTracks {0};
+  size_t m_numberOfSelectedTracks {0};
+
   void computeSharedHits(std::vector<IndexSourceLink>* sourceLinks, TrackFinderResult& results) const;
   std::shared_ptr<TrackFinderFunction> m_fit;
   std::shared_ptr<TrackFitterFunction> m_kf;