List machine rules

Lists display/raise/drop rules for the given scope: the optional machine query param is a machine public_id ('' or absent = global scope). The first global load seeds the default rule set. Each rule reports its id, source scope, event pattern, mode (1=hide,2=show,3=raise,4=drop), action (vestigial, always raise), polarity, label, enabled flag, sanitize_scope and match_on (the extra event fields a rule made from an event must also equal; empty for every other rule). 404 if the machine is not owned by the caller.

This is a read: a read-only API key may call it.