separate non-native key handling from IsUserPane

NSOpenGLView is needed under 10.14 as a native view, but it doesn’t have its own native key handling, therefore use the same code we have for non-native custom views.

include/wx/osx/cocoa/private.h

@@ -50,6 +50,7 @@ class WXDLLIMPEXP_FWD_CORE wxDialog;
 class WXDLLIMPEXP_CORE wxWidgetCocoaImpl : public wxWidgetImpl
 {
 public :
+    wxWidgetCocoaImpl( wxWindowMac* peer , WXWidget w, bool isRootControl, bool isUserPane, bool wantsUserKey ) ;
     wxWidgetCocoaImpl( wxWindowMac* peer , WXWidget w, bool isRootControl = false, bool isUserPane = false ) ;
     wxWidgetCocoaImpl() ;
     ~wxWidgetCocoaImpl();