Calling UpdateItem() may be performed by in a common loop, e.g. for(
SCH_ITEM* item : GetScreen()->Items() ) or similar. We cannot call
GetScreen()->Update( SCH_ITEM* ) in this routine as it will remove and
re-add the item to the RTree, invalidating iterators. If needed, the
items need to be cached to an external container before updating
Fixes https://gitlab.com/kicad/code/kicad/issues/9318
Mac already uses diverse font sizes (for instance, smaller fonts for
radio button groups), and the anti-aliasing is a lot better. The
other platforms need a more limited range of sizes.
Fixes https://gitlab.com/kicad/code/kicad/issues/8608