When we 'trip' an action in requestctl-generated VCL, it would be nice if we also made this visible to request logging.
AIUI the X-Analytics field is a freeform map, so we can simply append an extra field like requestctl_rule=foo where foo is the name of the action.
We should do this annotation even if a corresponding ratelimiting or synthesis of a 4xx/5xx code *didn't* happen -- this way we can use it to review actions over time.