Added count in project_type

What does this MR do and why?

Adds count to ProjectType for showing number of pages on UI pagination

Refs: https://gitlab.com/gitlab-org/gitlab/-/issues/346364

Screenshots or screen recordings

1. Verify that count isn't present for Projects on master branch

2. Verify count is present for Projects with the changes

How to set up and validate locally

1. Validate GraphQL projects have count in them, visit http://127.0.0.1:3000/-/graphql-explorer and use the following query

{
  projects {
    count
    edges {
      node {
        id
      }
    }
  }
}

2. Validate that count isn't resulting in an Error
3. Check for a valid response

{
  "data": {
    "projects": {
      "count": 2,
      "edges": [
        {
          "node": {
            "id": "gid://gitlab/Project/21"
          }
        },
        {
          "node": {
            "id": "gid://gitlab/Project/20"
          }
        }
      ]
    }
  }
}

MR acceptance checklist

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