fix(web): Add index property in hippy-element

Author: godky

driver/js/packages/hippy-vue-next/src/runtime/element/hippy-element.ts

@@ -919,6 +919,7 @@ export class HippyElement extends HippyNode {
         style,
       },
       tagName: this.tagName,
+      index: this.index,
     };
 
     // hack in dev environment, added properties for chrome inspector debugging