Add support for Qt6

src/qt/cocoa_mouse.hpp

@@ -1,10 +1,16 @@
 #include <QAbstractNativeEventFilter>
 #include <QByteArray>
 
+#if QT_VERSION_MAJOR >= 6
+#define result_t qintptr
+#else
+#define result_t long
+#endif
+
 class CocoaEventFilter : public QAbstractNativeEventFilter
 {
 public:
     CocoaEventFilter() {};
     ~CocoaEventFilter();
-    virtual bool nativeEventFilter(const QByteArray &eventType, void *message, long *result) override;
+    virtual bool nativeEventFilter(const QByteArray &eventType, void *message, result_t *result) override;
 };