Utils: Make the second parameter to LayoutBuilder::attach() an enum

More explicit and more potential options (e.g. "treat grid as form")
than a bool.

Change-Id: I89413efe30410160c38b0e524ba64288dde2332e
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/projectexplorer/runconfiguration.cpp

@@ -245,7 +245,7 @@ QWidget *RunConfiguration::createConfigurationWidget()
             aspect->addToLayout(builder.finishRow());
     }
 
-    auto widget = builder.emerge(false);
+    auto widget = builder.emerge(Layouting::WithoutMargins);
 
     VariableChooser::addSupportForChildWidgets(widget, &m_expander);