List all appointments

curl --request GET \
  --url https://api.caspen.com/v1/appointments

{
  "data": [
    {
      "id": "<string>",
      "location_id": "<string>",
      "practitioner_id": "<string>",
      "service_id": "<string>",
      "service_price": 123,
      "price": 123,
      "price_unit": "<string>",
      "price_per_client": true,
      "appointment_clients": [
        {
          "id": "<string>",
          "appointment_id": "<string>",
          "client_id": "<string>",
          "case_id": "<string>",
          "client_package_id": "<string>",
          "status": "<string>",
          "do_not_invoice": true,
          "note": "<string>",
          "confirmed": true,
          "confirmed_at": "<string>",
          "cancellation_reason_id": "<string>",
          "cancellation_note": "<string>",
          "cancelled_at": "<string>",
          "starts_at": "<string>",
          "ends_at": "<string>",
          "created_at": "<string>",
          "updated_at": "<string>"
        }
      ],
      "starts_at": "<string>",
      "ends_at": "<string>",
      "duration": 123,
      "status": "<string>",
      "room_id": "<string>",
      "vehicle_id": "<string>",
      "resource_ids": [
        "<string>"
      ],
      "note": "<string>",
      "cancellation_reason_id": "<string>",
      "cancellation_note": "<string>",
      "cancelled_at": "<string>",
      "created_at": "<string>"
    }
  ],
  "links": {
    "prev": "<string>",
    "next": "<string>"
  }
}