MacOSXCGLContext: NPE in DEBUG mode while releaseNSOpenGLLayer on main-thread, drawable maybe null already
OSX/NEWT: Fix visible -> false when closing and reparenting window. This lead to non functional recreational reparenting.

OSX recreational reparenting moves the saved GLEventListenerState at destroy
to the new dawable/surface, which must be valid.
The flaky visible state caused seemingly random reparenting failures.

- WindowImpl.ReparentActionRecreate.run() set 'visible:=true', which circumvented OSX to wait for actual realization.
- OSX WindowDriver.closeNative(): Issue visibleChanged(true, false); ASAP