- ITF14/DPLEIT/DPIDENT: ignore option_2 (check digit options)

- GUI: scalewindow: fix cropping resolution on initial setup
  (`spnResolution` max 1000 -> 254000) and bound X-dim to <= 10 in
  `set_maxima()`
- GUI: mainwindow: bound X-dim as above and clamp `m_xdimdpVars`
  members on initial load from INI
- GUI: undo `QString::mid()` -> `QString::midRef()` from clazy
  & explicitly include "QObject" in "qzint.h" (not Qt6 compatible)

backend_qt/qzint.h

@@ -24,6 +24,7 @@
 #ifndef QZINT_H
 #define QZINT_H
 
+#include <QObject>
 #include <QColor>
 #include <QPainter>
 #include "zint.h"