curl --request GET \
  --url http://localhost:8080/campaigns

{
  "items": [
    {
      "id": 123,
      "name": "<string>",
      "start_parameter": "<string>",
      "bonus_type": "balance",
      "balance_bonus_kopeks": 123,
      "balance_bonus_rubles": 123,
      "is_active": true,
      "created_at": "2023-11-07T05:31:56Z",
      "updated_at": "2023-11-07T05:31:56Z",
      "subscription_duration_days": 123,
      "subscription_traffic_gb": 123,
      "subscription_device_limit": 123,
      "subscription_squads": [
        "<string>"
      ],
      "tariff_id": 123,
      "tariff_duration_days": 123,
      "tariff_name": "<string>",
      "created_by": 123,
      "registrations_count": 0
    }
  ],
  "total": 123,
  "limit": 123,
  "offset": 123
}