ModelEditor: Apply naming convention to types

Use Pascal style for typedefs and class instead of struct.

Change-Id: Ib568994e70c8ac0a219b2fba1d998e04ef5f79da
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>

src/libs/3rdparty/modeling/qmt/diagram_controller/diagramcontroller.cpp

@@ -54,7 +54,9 @@
 
 namespace qmt {
 
-struct DiagramController::Clone {
+class DiagramController::Clone
+{
+public:
     Clone();
     Uid m_elementKey;
     int m_indexOfElement;