Video Object Tracking Annotations can't export to YOLOv5

**Is your feature request related to a problem? Please describe.**
I noticed that I can't export labels from a video object tracking task to YOLOv5 format. I think this is because YOLOv5 exports are only possible with Rectangle Annotations.

**Describe the solution you'd like**
It seems like it would be feasible to cut the video frames and interpolated rect dimensions up into the format expected by YOLOv5 and this would make the workflow pretty nice for getting a lot of labeled frames. Any plans to integrate this in the future, or perhaps this was an oversight or there's a technical limitation I'm not seeing?

**Describe alternatives you've considered**
If there's a way to use label studio converter to convert object tracking JSON to YOLOv5 format, I suppose that would solve the problem as well, while being a little less convenient.

I suppose there might also be a model other than YOLOv5 I'm not aware of that can readily accept the JSON data format provided by label studio from Video Object tracking and run with it.