Replace YAML approver info with persisted data

Merged Zamir Martins requested to merge replace_yaml_info_with_persisted_data_backend into master

What does this MR do and why?

Replace YAML approver info with persisted data in order to make this information available for the frontend .

This will allow for the removal of a similar method which is currently limited to this controller.

Related issue: #357301 (closed)

Frontend MR: !90521 (merged)

How to set up and validate locally

  1. Go to Security & Compliance -> Policies and create a scan result policies as per our docs with at least one approver.
  2. Go to graphql-explorer and query the scan result policies with approver information:
{
  project(fullPath: <PROJECT_FULL_PATH>){
    scanResultPolicies{
      nodes{
        name
        userApprovers {
          id
	  webUrl
        }
        groupApprovers {
          id
          webUrl
        }
      }
    }
  }
}

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

Edited by Zamir Martins