GH-998: Fix Reporter::conn_weird() to handle expired connections

This introduces a new sampling state-map for expired connections to fix
segfaults that previously occured when passing in a `connection` record
to `Reporter::conn_weird()` for which the internal `Connection` object
had already been expired and deleted.  This also introduces a new event
called `expired_conn_weird`, which is similar to `conn_weird`, except
the full `connection` record is no longer available, just the `conn_id`
and UID string.

src/Timer.h

@@ -15,6 +15,7 @@ enum TimerType : uint8_t {
 	TIMER_CONN_EXPIRE,
 	TIMER_CONN_INACTIVITY,
 	TIMER_CONN_STATUS_UPDATE,
+	TIMER_CONN_TUPLE_WEIRD_EXPIRE,
 	TIMER_DNS_EXPIRE,
 	TIMER_FILE_ANALYSIS_INACTIVITY,
 	TIMER_FLOW_WEIRD_EXPIRE,