fix: Avoid crashing when updated triggered before rendering

Author: SylvainBigonneau

src/core/componentStructure.js

@@ -1,4 +1,4 @@
-const getHtmlElementFromNode = ({ el }) => el;
+const getHtmlElementFromNode = ({ el }) => el || {};
 const addContext = (domElement, context) =>
   (domElement.__draggable_context = context);
 const getContext = domElement => domElement.__draggable_context;

src/vuedraggable.js

@@ -139,7 +139,7 @@ const draggableComponent = defineComponent({
   },
 
   updated() {
-    this.componentStructure.updated();
+    this.$nextTick(() => this.componentStructure.updated());
   },
 
   beforeUnmount() {