Get the materialised end user entities for an end user

curl --request GET \
  --url https://app.herondata.io/api/end_users/{end_user_heron_id}/entities \
  --header 'Authorization: Basic <encoded-value>'

[
  {
    "display_order": 123,
    "entity_heron_id": "<string>",
    "entity_name": "<string>",
    "is_list": true,
    "materialised_attributes": [
      {
        "attribute_heron_id": "<string>",
        "attribute_name": "<string>",
        "display_order": 123,
        "materialised_sources": [
          {
            "source": {
              "heron_id": "<string>",
              "sort_order": 123,
              "source_config": {},
              "source_type": "parsed_end_user_file"
            },
            "source_data": {},
            "timestamp": "2023-11-07T05:31:56Z",
            "value": "<any>"
          }
        ],
        "selected_source": {
          "source": {
            "heron_id": "<string>",
            "sort_order": 123,
            "source_config": {},
            "source_type": "parsed_end_user_file"
          },
          "source_data": {},
          "timestamp": "2023-11-07T05:31:56Z",
          "value": "<any>"
        }
      }
    ]
  }
]