common: Fix "selectable" state of the ListRow InfoButton
Originally the screen reader wasn't reading the text of the label within the popover. It read when we set label.selectable = True. That had the side-effect of making the label have the visual look of a selectable label (as expected).
This hack unsets the selectable state of the popover when it is visible, but that still allows the screen reader to read the label.
Fixes #2508 (closed)