some refactoring and make highlighter change when app changed

frontend/src/pages/FlowChart.vue

@@ -290,20 +290,8 @@ const onSaveAllFlow= async ()=>{
 }
 
 const fetchData = async () => {
+  await store.loadFlow();
   drawerLeft.value = true;
-  if (store.appInfo === undefined) return;
-  const flowCtrl = new FlowCtrl();
-  const actionFlows = await flowCtrl.getFlows(store.appInfo?.appId);
-  if (actionFlows && actionFlows.length > 0) {
-    store.setFlows(actionFlows);
-  }
-  if (actionFlows && actionFlows.length == 1) {
-    store.selectFlow(actionFlows[0]);
-  }
-  const root = actionFlows[0].getRoot();
-  if (root) {
-    store.setActiveNode(root);
-  }
 }
 
 const onClearFilter=()=>{