Support for `NSValue`/`CGAffineTransform` exists in iOS/tvOS/watchOS,
from UIKit, but not for macOS. However this will be required for the
new protocols inside CoreImage.
Also add an overload for `StoreValueAtAddress` since the original
one was deprecated but we did not provide the new alternative to
update the code.
- Fixes#4698: CGAffineTransform.Scale does not work like Swift's .scaledBy(x:y:)
(https://github.com/xamarin/xamarin-macios/issues/4698)
- 'Scale' monotouch-test now covers the new overload for the new multiplication order.
- Changed the Scale test's values so we have different values for 'x0' (it was always 0 before) and so it matches the test case from the bug report.
* Same fix for Rotate and Translate
Rolf Bjarne Kvinge
Marius Ungureanu
Sebastien Pouliot
Vincent Dondain