Go always back to the base state if you change the state

Should work without this, but the performance hit is not so high,
and this is more robust to changes in the qml state code.

Task-Number: BAUHAUS-660
Reviewed-by: kkoehne

src/plugins/qmldesigner/designercore/instances/nodeinstanceview.cpp

@@ -616,6 +616,7 @@ NodeInstance NodeInstanceView::loadNode(const ModelNode &node, QObject *objectTo
 
 void NodeInstanceView::activateState(const NodeInstance &instance)
 {
+    activateBaseState();
     NodeInstance stateInstance(instance);
     stateInstance.activateState();
 }