templateview.h: add missing QGraphicsGridLayout/QGraphicsLayoutItem includes

templateview.h only included <QGraphicsView> but uses
QGraphicsGridLayout (tbgrid_ member) and QGraphicsLayoutItem
(indexOf/removeItem signatures) directly. Some Qt5 header
apparently pulled these in transitively; Qt6's leaner headers
don't, so the class fields/methods silently failed to resolve
and the compiler picked bogus 'int*' overloads instead.
Other files in the same directory already get these symbols
either via the <QtWidgets> umbrella header or a direct include,
so this was an isolated gap.

sources/titleblock/templateview.h

@@ -20,6 +20,8 @@
 #include "../titleblocktemplate.h"
 
 #include <QGraphicsView>
+#include <QGraphicsGridLayout>
+#include <QGraphicsLayoutItem>
 class HelperCell;
 class SplittedHelperCell;
 class TitleBlockTemplateCommand;