[Code Improvement] dc_ajax_add_cart.refresh_page_elements_helper should be responsible for updating add to cart form

Problem/Motivation

Since RefreshPageElementsHelper is converted to a service (#2919633: [Code Improvement] Use container for loading services in RefreshPageElementsHelper). It is recommended the ajax UpdateBuildIdCommand should also be moved inside the service.

It should have been moved earlier, I must have missed it.

Proposed resolution

Move ajax UpdateBuildIdCommand inside dc_ajax_add_cart.refresh_page_elements_helper service.

Remaining tasks

Add new kernel tests that would support the change in the service.

User interface changes

N/A

API changes

N/A

Data model changes

N/A