Fix label pill table cell styling issue

[nathanielrindlaub]

Label pill cells in the ImagesTable are getting set to scrollable when it shouldn't be (it is because we count all objects in an image, including invalidated ones that don't get displayed).

In general the label pill cells could use a little styling love. When labels are long, the pills wrap to two lines and make the pills look terrible.

Also maybe we should come up with a more inteligent way to set the cell to scrollable (whatever the current object count threshold is, it appears to be too high, b/c sometimes the cell doesn't get set to scrollable and the labels spill out of the top and bottom of the cell).