Effect Maker: Notice property changes in helper nodes

Property changes in helper nodes are now properly noticed as unsaved
changes.

Change-Id: I757f519075d2f96be2b84b57b25b916665e26ba7
Reviewed-by: Qt CI Patch Build Bot <ci_patchbuild_bot@qt.io>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/plugins/effectmakernew/effectmakermodel.cpp

@@ -124,6 +124,10 @@ void EffectMakerModel::addNode(const QString &nodeQenPath)
 
             const QString path = EffectUtils::nodesSourcesPath() + "/common/" + requiredId + ".qen";
             auto requiredNode = new CompositionNode({}, path);
+            connect(qobject_cast<EffectMakerUniformsModel *>(requiredNode->uniformsModel()),
+                    &EffectMakerUniformsModel::dataChanged, this, [this] {
+                        setHasUnsavedChanges(true);
+                    });
             requiredNode->setRefCount(1);
             m_nodes.prepend(requiredNode);
         }