Add issueLinks to PipelineSecurityReportFinding

What does this MR do and why?

This MR adds the issueLinks field to the PipelineSecurityReportFinding GraphQL type.

Screenshots or screen recordings

How to set up and validate locally

1. Run a pipeline on a main branch of a project
   • Sample project
2. Create an issue for a security finding
3. Run the following GraphQL query. You should see the issue data

{
  project(fullPath: "<project_path>") {
    pipeline(iid: "1") {
      id
      securityReportFindings {
        nodes {
          title
          uuid
          issueLinks {
            nodes {
              issue {
                description
              }
            }
          }
        }
      }
    }
  }
}

MR acceptance checklist

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

• I have evaluated the MR acceptance checklist for this MR.

Related to #384867 (closed)