Fetch contacts in pages.
Example Result:
{
  contacts: [
    {
      id: 1,
      external_id: "yourid",
      name: "Fred Smith",
      first_name: "Fred",
      last_name: "Smith",
      zip: "97701",
      address_book_id: 123,
      address_book_name: "Apptoto Address Book",
      writable: true,
      notes: "Long string of notes",
      deleted: false,
      phone_numbers: [
        {
          id: 3,
          number: "650-555-1212",
          normalized: "+16505551212",
          type: "mobile",
          is_primary: true
        }
      ],
      email_addresses: [
        {
          id: 4,
          address: "fredsmith@gmail.com",
          type: "work"
        }
      ],
      custom_data: {
        field_1: "vip"
      }
    }
  ]
}