Add GraphQL query for deployment details

NOTE: This MR is built on top of !95255 (merged)

What does this MR do and why?

This MR adds GraphQL query for fetching deployment information. As described in the issue, this query can be extended for many purposes, such as

• Usage example: Show tags related to deployed commit on Environment Page
• Usage example: Show tags related to deployed commit on Environment Detail Page
• Usage example: Deployment Issue (Deployment detail page)
• Usage example: Update GraphQL API to support environment detail page

Query example

Get details of the deployment

{
  project(fullPath: "root/pipeline-playground") {
    deployment(iid: 10) {
      tag_names_contains_sha # To be supported in https://gitlab.com/gitlab-org/gitlab/-/issues/15419
    }
  }
}

Screenshots or screen recordings

How to set up and validate locally

Access to GraphiQL and try execute the above queries.

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.