New: Cleanup UI tooling, Update to Webpack 4, Gulp 4 (#655)

* New: Webpack 4

* New: Gulp 4

* New: Transpile UI for old browsers

Co-Authored-By: Mark McDowall <markus101@users.noreply.github.com>

frontend/src/Utilities/requestAction.js

@@ -1,5 +1,6 @@
 import $ from 'jquery';
 import _ from 'lodash';
+import createAjaxRequest from './createAjaxRequest';
 
 function flattenProviderData(providerData) {
   return _.reduce(Object.keys(providerData), (result, key) => {
@@ -34,7 +35,7 @@ function requestAction(payload) {
     ajaxOptions.url += `?${$.param(queryParams, true)}`;
   }
 
-  return $.ajax(ajaxOptions);
+  return createAjaxRequest(ajaxOptions).request;
 }
 
 export default requestAction;