Delete campaign

curl --request DELETE \
  --url https://app.usesend.com/api/v1/campaigns/{campaignId} \
  --header 'Authorization: Bearer <token>'

{
  "id": "<string>",
  "name": "<string>",
  "from": "<string>",
  "subject": "<string>",
  "previewText": "<string>",
  "contactBookId": "<string>",
  "html": "<string>",
  "content": "<string>",
  "status": "<string>",
  "scheduledAt": "2023-11-07T05:31:56Z",
  "batchSize": 123,
  "batchWindowMinutes": 123,
  "total": 123,
  "sent": 123,
  "delivered": 123,
  "opened": 123,
  "clicked": 123,
  "unsubscribed": 123,
  "bounced": 123,
  "hardBounced": 123,
  "complained": 123,
  "replyTo": [
    "<string>"
  ],
  "cc": [
    "<string>"
  ],
  "bcc": [
    "<string>"
  ],
  "createdAt": "2023-11-07T05:31:56Z",
  "updatedAt": "2023-11-07T05:31:56Z"
}