Show only Archived Projects in group.projects graphQL

What does this MR do and why?

Show only Archived Projects in group.projects graphQL

Add a archived_only filter param to the group.projects graphQL https://docs.gitlab.com/api/graphql/reference/#groupprojects

This is going to be used to filter projects which are archived in the Compliance project report, ref Compliance Center Enhancement: Display and Filt... (#500520 - closed)

Database query plan

https://console.postgres.ai/gitlab/gitlab-production-main/sessions/36725/commands/112776

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Before	After

How to set up and validate locally

1. Ensure that you have a group with mutiple projects, including at least one archived project
2. Run the following query:

query {
  group(fullPath: "your-group-path") {
    projects(archivedOnly: true) {
      nodes {
        id
        name
        archived
      }
    }
  }
}

3. You should only see the projects that are archived
4. Replace archivedOnly: false
5. You should only see the projects that are not archived
6. Remove the archivedOnly filter
7. You should only see all projects

Related to #500520 (closed)