Fix bug: distance filtering resulting in unmatched tracking ids

[a1600012888]

Hi, I fixed a bug in the post processing step inNuScenesTrackDataset._format_bbox.

This bug will produce mis-matched tracking indexs, results in a large drop in AMOTA, but leaves the RECALL not changed too much.

The bug is cuased by

MUTR3D/plugin/track/dataset.py

Line 871 in c2fde4e

if radius > det_range:

MUTR3D/plugin/track/dataset.py

Line 588 in c2fde4e

tracking_id=str(det['track_ids'][i].item()),

When I removed the boxes that are out of the range, the tracking id need to be changed too.
Now I merge the tracking id, score into the new Class NuScenesTrackingBox: https://github.com/a1600012888/MUTR3D/blob/main/plugin/track/dataset.py#L796.
Then the mismatch of tracking ids caused from removing boxes is fixed.