Improve grid cell calculator

* Use full name for grid case view
* FIx signed / unsigned issue
* Support drag/drop of file names into Main Window
* Add function to check if two grid cases are of equal size
* Result Info: Show cell result text for all linked views
* Improve how to specify cells to be included in calculation

- move view filter to calculation
- improve how to assign values to non-visible cells
- avoid computation between grids of different size

Closes #9482

ApplicationLibCode/UserInterface/RiuMainWindow.h

@@ -138,6 +138,9 @@ protected:
     QStringList defaultDockStateNames() override;
     QStringList windowsMenuFeatureNames() override;
 
+    void dragEnterEvent( QDragEnterEvent* event ) override;
+    void dropEvent( QDropEvent* event ) override;
+
 private:
     void createActions();
     void createMenus();