Port away from more QLinkedLists
QLinkedList is gone from Qt6
The 1:1 port is std::list but we don't need iterator stability on removal/insertion so just port to QList (one case to QVector since QList needs a copy constructor)
QLinkedList is gone from Qt6
The 1:1 port is std::list but we don't need iterator stability on removal/insertion so just port to QList (one case to QVector since QList needs a copy constructor)