Distinguish Candidate, Operations, and System Actors in Audit Log Entries

auditLog.list now returns Candidate, Operations, and System as possible values of actor.type, alongside the existing User, ApiUser, Automation, Support, and Other.
Actions previously reported as User are now identified precisely: Candidate for actions a candidate took in the candidate portal, Operations for actions Ashby staff took using internal tooling, and System for internal processes such as migrations and scheduled jobs. If you branch on actor.type, handle these three new values.
actor.id for a Candidate entry is the candidate's id. The candidate's name is never returned in actor.name.