Retrieve one product

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

{
  "id": "<string>",
  "source_ref": {
    "id": "<string>",
    "model": "<string>"
  },
  "name": "<string>",
  "unit_price": 123,
  "tax_id": "<string>",
  "code": "<string>",
  "unit": "<string>",
  "category": "<string>",
  "currency": "<string>",
  "description": "<string>",
  "cost": 123,
  "available_quantity": 123
}