List destinations

curl --request GET \
  --url https://api.portable.io/v2/destinations \
  --header 'Authorization: Bearer <token>'

{
  "data": [
    {
      "id": 123,
      "displayName": "<string>",
      "destinationSpec": "<string>",
      "createdAt": "2023-11-07T05:31:56Z",
      "updatedAt": "2023-11-07T05:31:56Z"
    }
  ]
}