Get the alerts that share threat infrastructure with one alert, for
example a shared name server, registrant, or hosting provider. Provide
exactly one of id or entity to identify the alert.

The response holds a thin summary of each connected alert, newest first,
and names only the alerts GET /v2/alert returns for you. Use
GET /v2/alert with a returned id for the full alert.

Requires the Threat Graph Insights product. Without it, and for an alert
you cannot read, the response is 404.
The organization is determined from the org_id claim in the JWT.