Get EndUser metric benchmarks

curl --request GET \
  --url https://app.herondata.io/api/end_users/{end_user_id_or_heron_id}/benchmarks \
  --header 'x-api-key: <api-key>'

{
  "benchmarks": [
    {
      "date_range": "last_180_days",
      "label": "unique_transactions",
      "percentile": 0.75,
      "rank": 22,
      "sample_size": 42,
      "scope": "user"
    }
  ]
}