A way to easily verify label assignment

[lastant]

It would be very useful to be able to have a quick overview of all assigned labels, grouped by the class, then one could easily see if there are any wrong labels.
I created a script to create this kind of an overview (https://github.com/lastant/yolo-annotations-verify) but hopefully Label Studio can offer this out of the box.

[makseq]

Please check this PR:
#5909

It allows you to cache labels as a new data column:

[lastant]

I mean seeing the actual cropped-out bounding boxes themselves. The small images. If you see all bounding boxes of a specific class from all tasks you can quickly identify misclassified boxes. Otherwise it's very difficult to notice a mistake (when a class of a box is wrong or when a box is totally misplaced), and this seriously damages the model. I've noticed a lot of mistakes in my annotations using the script I provided, and I was labeling quite attentively.