List child organizations

Example response

{
  "children": [
    {
      "id": "550e8400-e29b-41d4-a716-446655440000",
      "name": "child-org",
      "projectCount": 5,
      "applicationCount": 12,
      "userCount": 8
    }
  ],
  "invites": [
    {
      "id": "550e8400-e29b-41d4-a716-446655440000",
      "name": "organization-name"
    }
  ]
}