List coupons

curl --request GET \
  --url https://api.shoppex.io/dev/v1/coupons \
  --header 'Authorization: Bearer <token>'

{
  "data": [
    {
      "id": "coupon_db_1",
      "uniqid": "coupon_1",
      "shop_id": "shop_1",
      "type": "PERCENTAGE",
      "code": "save10",
      "discount": 10,
      "used": 2,
      "max_uses": 100,
      "min_order_amount": 20,
      "max_discount": 50,
      "valid_from": 1711929600,
      "valid_until": 1714521600,
      "is_active": true,
      "created_at": 1711929600,
      "updated_at": 1711933200,
      "products_bound": [],
      "products_count": 1
    }
  ],
  "pagination": {
    "next_cursor": null,
    "has_more": false
  }
}