Icons too big in worker mgmt app

[kingjon3377]

In the worker management app, depending on the user's platform icons will either cause rows of the unit tree that have them to be expanded to a height that is unwieldy, or cause the icons to be truncated to fit the rows' height. I'm not sure how to go about scaling them down to a more reasonable height, though. (Especially since we do want them to scale up if the user's system has a setting, such as font size, that causes the rows' height to increase.)