Pop-up Overhaul

[birdddev]

RevealUI (FavBar draft/app icons, requirements/tooltips) and Menus (combos/dropdowns, search enum) should re-use an underlying PopUp widget.
This should keep logic and visual consistency between them, similar to how InputBoolUI is used in place of check-boxes now.

<PopUp></PopUp>

• Should prevent itself from having any part of the pop-up go off-screen
• Close based on distance outside of pop-up and on-click outside of pop-up (Clicking outside a pop-up should probably prevent event propagation)

[rvion]

Combos/dropdowns are also using RevealUI
and I was planning to make selectUI also use it;
I want to polish RevealUI widget quite a lot, cause it's going to be a key component; really want to get it right;
I was among other things planning to handling nested Reveal Properly too via react context and push/pop within a single root reveal state

[birdddev]

Should I rename <RevealUI> to <PopUp>/<PopUpUI> and then work from there?
Making SelectUI use it as well.