DIVE - Track Confidence Filter and meta.JSON [BUG]

[BryonLewis]

Describe the bug
Quickly setting the confidence filter multiple times, then jumping back to recents, then trying to load a dataset will cause an error to occur.

To Reproduce
Steps to reproduce the behavior:

1. Open a datset in DIVE
2. Quickly adjust the threshold be sure to release it each time.
3. Quickly return back to recents and try to load another dataset
4. Notice that the next dataset will load the tracks, but not the images/video.
5. It may eventually load the tracks, but in my case it took over 2 minutes for it to complete the request for the meta.json.

Expected behavior
To load the next dataset.

Additional context
I didn't look into it, but I imagine it's an issue with queuing up all of those meta.json changes and writing them quickly then something with trying to access that file afterwards.

[BryonLewis]

@subdavis - It doesn't technically crash the system, but could take minutes to load the data after switching.