Perhaps many of these popovers could use a design pass in 2.91, for 2.90 we don't
want to change any UI strings at this state, so the best way to solve the cutoff text
is to widen the popovers. Sadly this won't affect popovers when other languages besides
English have longer strings, but solving that is a much larger task.

Another benefit is that tweaking sculpt / paint brush options feels much less cramped
with slightly wider popovers.

I only know of one string that is still slightly cutoff by default with this patch, the
Max Element Distance property of the pose brush in the sculpt mode brush settings popover.
But I didn't think it was worth widening that popover more to deal with that one case.