Retrieve one opportunity

curl --request GET \
  --url https://api.chift.eu/consumers/{consumer_id}/invoicing/opportunities/{opportunity_id} \
  --header 'Authorization: Bearer <token>'

{
  "id": "<string>",
  "source_ref": {
    "id": "<string>",
    "model": "<string>"
  },
  "name": "<string>",
  "total": 123,
  "probability": 123,
  "status": "open",
  "partner_id": "<string>",
  "comment": "<string>",
  "currency": "<string>",
  "description": "<string>",
  "pipe_status": "<string>",
  "pipe_name": "<string>",
  "created_date": "2023-12-25",
  "due_date": "2023-12-25",
  "end_date": "2023-12-25",
  "is_won": true,
  "owner_ref": {
    "id": "<string>",
    "model": "<string>",
    "name": "<string>"
  }
}