[HER-1827] Have Frontier report include top X longest queues

* WorkQueueFrontier.java
    improve effective precision of top-n-queues by also updating on dequeues

engine/src/main/java/org/archive/crawler/frontier/WorkQueueFrontier.java

@@ -1000,6 +1000,7 @@ implements Closeable,
         // Curi will definitely be disposed of without retry, so remove from queue
         wq.dequeue(this,curi);
         decrementQueuedCount(1);
+        largestQueues.update(wq.getClassKey(), wq.getCount());
         log(curi);