Add non-system-border option on Windows

Sine Striker

2023-12-22 c837319767bb609c6ec806336e49a347c77b11d3

 src/core/windowitemdelegate.cpp

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

    WindowItemDelegate::~WindowItemDelegate() = default;

    void WindowItemDelegate::resetQtGrabbedControl() const {}
    void WindowItemDelegate::resetQtGrabbedControl(QObject *host) const {
        Q_UNUSED(host);
    }

}