winemac: When programmatically focusing a window, don't generate WINDOW_LOST_FOCUS event for previously focused window.
That event can confuse things if the program switches focus from A to B and
then back to A and then processes events. It will get an event saying that
A lost focus in Cocoa, check that A does indeed have current focus in Wine,
and so switch focus away from it (to the desktop window). (It then gets an
event that B lost focus, but that does nothing at that point.)
(cherry picked from commit
4e0e9ca84a89d1ac2b548ee4a6224b764af2d23d)