Add projects for Organization resolver

What does this MR do and why?

Add projects for Organization display

• show projects for an organization.
• see #423327 (closed)

Screenshots or screen recordings

How to set up and validate locally

1. go to http://gdk.test:3000/-/graphql-explorer
2. input the below:

{
  organization(id: "gid://gitlab/Organizations::Organization/1") {
    projects(first: 5, after: null) {
      nodes {
        id
        name
      }
      pageInfo {
        startCursor
        endCursor
        hasNextPage
        hasPreviousPage
      }
    }
  }
}

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 #423327 (closed)