Profile BlockEntry (summary)
BlockEntry could be either of kind Content or Profile materialized by nullable
content_id or relation_id{
"id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",
"content_id": "713e4c61-5a69-43fb-a600-2e2699462e14",
"relation_id": "db83d865-cb76-4d51-8e9b-097dfcf4e259"
}