Table can be splitted and and row number limited

1.Table can have a name.
2.User can define the maximum row to display.
3.Table can be linked together, this is useful when there is a large
data to display in a single table.

Point 1, 2 and 3 work like this :

-Name a table (point 1).
-Limit the number of row to display to fit the table into a diagram
(point 2).
-Create a second table in a new folio.
-Link the second table to first table, you can search by table name
(point 3).
-the new table start to display where the first table end.
The number of linked table is unlimited.

sources/qetgraphicsitem/ViewItem/qetgraphicsheaderitem.h

@@ -46,7 +46,7 @@ class QetGraphicsHeaderItem : public QGraphicsObject
 		enum { Type = UserType + 1301 };
 		int type() const override { return Type; }
 
-        void setModel(QAbstractItemModel *model);
+		void setModel(QAbstractItemModel *model = nullptr);
         QAbstractItemModel *model() const;
 
         virtual QRectF boundingRect() const override;