Implement Cursor Locking and new input focus checks for it

Source/Core/Core/Core.h

@@ -169,6 +169,6 @@ void HostDispatchJobs();
 
 void DoFrameStep();
 
-void UpdateInputGate(bool require_focus);
+void UpdateInputGate(bool require_focus, bool require_full_focus = false);
 
 }  // namespace Core