Backends: OSX: Update to use io.AddEventKey() will full key map (#2625, #1873, #4858)

examples/example_apple_opengl2/main.mm

@@ -36,15 +36,6 @@
 
 -(void)initialize
 {
-    // Some events do not raise callbacks of AppView in some circumstances (for example when CMD key is held down).
-    // This monitor taps into global event stream and captures these events.
-    NSEventMask eventMask = NSEventMaskKeyDown | NSEventMaskKeyUp | NSEventMaskFlagsChanged;
-    [NSEvent addLocalMonitorForEventsMatchingMask:eventMask handler:^NSEvent * _Nullable(NSEvent *event)
-    {
-        ImGui_ImplOSX_HandleEvent(event, self);
-        return event;
-    }];
-
     // Setup Dear ImGui context
     // FIXME: This example doesn't have proper cleanup...
     IMGUI_CHECKVERSION();