win: allow dynamic switch dark mode

Zhao Yuhang

2023-12-22 e33059ee1ef7e1be07490ad0245676ded42589f4

 src/core/contexts/win32windowcontext_p.h

@@ -40,6 +40,8 @@

    protected:
        void winIdChanged() override;
        bool windowAttributeChanged(const QString &key, const QVariant &attribute,
                                    const QVariant &oldAttribute) override;

    public:
        bool windowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam, LRESULT *result);