Update EndUser P&L layout

curl --request PUT \
  --url https://app.herondata.io/api/end_users/{end_user_id_or_heron_id}/profit_and_loss_layout \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '{
  "category_labels": [
    "Postage"
  ],
  "section_slug": "operational_expenses"
}'

{
  "sections": [
    {
      "labels": [
        "<string>"
      ],
      "metrics": [
        {
          "denominator": {
            "labels": [
              "<string>"
            ],
            "sections": [
              "<string>"
            ]
          },
          "indent": 123,
          "is_growth": true,
          "name": "<string>",
          "numerator": {
            "labels": [
              "<string>"
            ],
            "sections": [
              "<string>"
            ]
          }
        }
      ],
      "name": "<string>",
      "slug": "<string>"
    }
  ]
}