Add JS für ESM

Now you can load the js file with es6 module loading

import { AjaxForm } from '../../../../../Packages/Application/Onedrop.AjaxForm/Resources/Public/JavaScript/form.esm';

let ajaxForms = document.querySelectorAll('[data-ajax="ajax-form"]');
for (let i = 0; i < ajaxForms.length; i++) {
    new AjaxForm(ajaxForms.item(i));
}