As per email feedback from Mozilla's
https://github.com/brampitoyo
This is yet another incremental step toward
redesigning the UI, much more is left to do.
The idea is to align uBO's UI to that of
Firefox Preview.
Additionally, code has been added to reset
the new popup panel to vertical layout should
the viewport be not wide enough to
accomodate the horizontal layout.
Related feedback:
- https://www.reddit.com/r/uBlockOrigin/comments/g4ufvi/