UI|Client|ChoiceWidget: Choice popups are opaque

ChoiceWidget's popup may already be over a couple of layers of widgets,
so making it fully opaque improves readability.

Todo for later: Blurring would also be ok.
UI|Console|Client: Console log is closed when command line loses focus

Makes it easier to dismiss the log, and makes the view less cluttered
when accessing non-console related parts of the UI.