Add new icons for unified banner and icon debug page.
Review Request #12732 — Created Nov. 18, 2022 and submitted
The design for the new unified banner includes a few new icons, which
hadn't yet been added to our spritesheet.
In order to make it easier to add new icons or identify existing ones,
I've also added a debug view which shows all of the icons (with bounding
It turns out that I'd also mistakenly committed an icons.afdesign file a
while ago. I've deleted in here.
Loaded /debug/icons/ and saw all of the icons, including new ones.