Add unit test for bounded compaction job priority queue

[keith-turner]

In #3460 a new bounded priority queue was created to hold compaction jobs in the manager. This new class needs unit test.

[dlmarion]

@keith-turner - Curious if you evaluated Guava 33.0's MinMaxPriorityQueue when you created CompactionJobPriorityQueue.

[dlmarion]

HBase also has https://github.com/apache/hbase/blob/master/hbase-server/src/main/java/org/apache/hadoop/hbase/util/BoundedPriorityBlockingQueue.java

[keith-turner]

Curious if you evaluated Guava 33.0's MinMaxPriorityQueue when you created CompactionJobPriorityQueue.

Yeah I did. One reason I did not use was the following comment on the javadoc. So when trying to use it as a bounded size prio Q it seems like it would be slow.

If you only access one end of the queue, and don't use a maximum size, this class is functionally equivalent to PriorityQueue, but significantly slower.

A second reason I did not use was because when new jobs are added for a tablet, need to efficiently remove any previous jobs related to the tablet that happen to be in the queue.

[keith-turner]

Wrong comment from the javadoc, the following was the comment I was looking at

If you only access one end of the queue, and do use a maximum size, this class will perform significantly worse than a PriorityQueue with manual eviction above the maximum size. In many cases Ordering.leastOf(java.lang.Iterable, int) may work for your use case with significantly improved (and asymptotically superior) performance.