Feature: #99626 - Sites configuration (YAML) in configuration module 

See forge#99626

Description 

Currently, it is difficult to have a global overview of the YAML configuration of sites (especially the route enhancers). Since those configurations are basic information, it is important for site administrators to have an overview of them.

Therefore, the configuration module now lists all site configurations with their identifier and corresponding configuration.

Impact 

It is now possible for site administrators to get an overview of the YAML configuration of all sites in the configuration module.