[Code Improvement] Use container for loading services in RefreshPageElementsHelper

Problem/Motivation

It is a best practice to load services from the container. Read Lesson 8.3 - Dependency injection. Instead of statically loading services, use the container to load the services.

Proposed resolution

Change code in RefreshPageElementsHelper class. Load service from container.

Remaining tasks

Update kernel tests if necessary.

User interface changes

N/A

API changes

RefreshPageElementsHelper itself has to become a service. So we can no longer instantiate a new RefreshPageElementsHelper like this new RefreshPageElementsHelper(new AjaxResponse()). Instead RefreshPageElementsHelper has to be loaded from the container.

Data model changes

N/A