Static global objects should be avoided if possible. The only reason we needed this QMap as global static was because of its usage in ArchiveModelSorter, but this class is gone as of D3271. So we can just make the QMap a member of the model.

While at it, make it a QMap<int, QByteArray> instead of QMap<int, QString>. This avoids the need of converting back (using QString::toUtf8()).

Works