add more user settings and qsettings group path, re #12610

Code/Mantid/MantidQt/CustomInterfaces/inc/MantidQtCustomInterfaces/EnggDiffraction/EnggDiffCalibSettings.h

@@ -36,6 +36,8 @@ struct EnggDiffCalibSettings {
   std::string m_inputDirRaw;
   std::string m_pixelCalibFilename;
   std::string m_templateGSAS_PRM;
+  bool m_forceRecalcOverwrite;
+  float m_rebinCalibrate;
 };
 
 } // namespace CustomInterfaces

Code/Mantid/MantidQt/CustomInterfaces/inc/MantidQtCustomInterfaces/EnggDiffraction/EnggDiffractionViewQtGUI.h

@@ -110,6 +110,9 @@ private:
   // window (custom interface) close
   virtual void closeEvent(QCloseEvent *ev);
 
+  // path/name for the persistent settings group of this interface
+  std::string m_settingsGroup;
+
   // here the view puts messages before notifying the presenter to show them
   std::vector<std::string> m_logMsgs;