Upsert usage records for contract obligations

curl --request POST \
  --url https://api.dualentry.com/public/v1/contracts/{contract_id}/usage/bulk-upsert/ \
  --header 'Content-Type: application/json' \
  --header 'X-API-KEY: <api-key>' \
  --data '
{
  "items": [
    {
      "obligation_id": 123,
      "usage_date": "2023-12-25",
      "quantity": 1,
      "id": 123,
      "rate": 123,
      "memo": "<string>",
      "classifications": [
        {
          "id": 123,
          "name": "<string>",
          "line_id": 123,
          "line_name": "<string>",
          "parent_classification_id": 123,
          "parent_classification_line_id": 123
        }
      ]
    }
  ]
}
'

[
  {
    "id": 123,
    "contract_id": 123,
    "obligation_id": 123,
    "usage_date": "2023-12-25",
    "quantity": "<string>",
    "amount": "<string>",
    "effective_rate": "<string>",
    "created_at": "2023-11-07T05:31:56Z",
    "updated_at": "2023-11-07T05:31:56Z",
    "rate": "<string>",
    "revenue_recognition_id": 123,
    "invoice_status": "<string>",
    "memo": "",
    "classifications": []
  }
]