Text Editor: make whitespace visible only when selected
The current implementation allows users to configure which type of whitespace (leading v.s. trailing) to show (as mentioned in GNOME/gnome-text-editor#525 (closed)), which is nice already. However, VS Code offers an additional choice: “selection”. If I choose it, then VS Code makes whitespaces visible only when I select some text. It would be nice if Text Editor can support this mode as well.