fix(tree): fix tree node not render in lazy (#1298)

Because `this` pointer is points to origin object in constructor.

packages/tree/src/model/tree-store.ts

@@ -41,7 +41,9 @@ export default class TreeStore {
     }
 
     this.nodesMap = {}
+  }
 
+  initialize() {
     this.root = new Node({
       data: this.data,
       store: this,

packages/tree/src/tree.vue

@@ -152,6 +152,9 @@ export default defineComponent({
       defaultExpandAll: props.defaultExpandAll,
       filterNodeMethod: props.filterNodeMethod,
     }))
+
+    store.value.initialize()
+
     const root = ref<Node>(store.value.root)
     const currentNode = ref<Node>(null)
     const el$ = ref<Nullable<HTMLElement>>(null)