EffectMaker: Show current composition name

Fixes: QDS-11442
Change-Id: I047040e42fd60c00abe2be7e2210fc8bb53678cb
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>
Reviewed-by: Amr Elsayed <amr.elsayed@qt.io>
Reviewed-by: Qt CI Patch Build Bot <ci_patchbuild_bot@qt.io>

src/plugins/effectmakernew/effectmakermodel.cpp

@@ -150,6 +150,7 @@ void EffectMakerModel::clear()
     qDeleteAll(m_nodes);
     m_nodes.clear();
     endResetModel();
+    setCurrentComposition("");
 
     setIsEmpty(true);
     emit nodesChanged();