Expose Analysis Service Evaluation Queue Count

For complex systems it is important to monitor the PI Analysis Service closely. The existing performance counters are helpful but we would really like the EvaluationQueueCount to be available as well. This would help determine if the EvaluationsToQueueBeforeSkipping limit is being approached, and also provide insight into whether changing NumberEvaluationThreads or other configuration parameters would help performance. We can watch it in the PSE Management area but it's not stored anywhere.