Reorganized folders to try to clean up the root folder a bit

public/assets/vendor/popper.js/packages/test-utils/utils/customEventPolyfill.js

@@ -0,0 +1,21 @@
+(function() {
+  if (typeof window.CustomEvent === 'function') {
+    return false;
+  }
+
+  function CustomEvent(event, params) {
+    params = params || { bubbles: false, cancelable: false, detail: undefined };
+    const evt = document.createEvent('CustomEvent');
+    evt.initCustomEvent(
+      event,
+      params.bubbles,
+      params.cancelable,
+      params.detail
+    );
+    return evt;
+  }
+
+  CustomEvent.prototype = window.Event.prototype;
+
+  window.CustomEvent = CustomEvent;
+})();