Undo your own false-alarm or non-threatening close

Takes back the caller's own single-event FALSE_ALARM or SUSPICIOUS_MONITOR close within 10 seconds of it (database clock, plus a 2 s latency allowance): the evaluation and any training sample captured from it are deleted, the alarm returns to the queue, and the caller takes its claim. 404 when the event is unknown or has no close to undo (including a second undo), 403 out of scope, missing the review_label_alarms permission, or the close was made by another operator or the agent; 409 "Too late to undo this close" after the window, 409 "This close can't be undone" for an escalation, a bulk close, or an audited close.