[EAGLE-978] change max(absoluteUsedCapacity) to avg() in queueCtrl.js

https://issues.apache.org/jira/browse/EAGLE-964
https://issues.apache.org/jira/browse/EAGLE-978

* change max(absoluteUsedCapacity) to avg() in queueCtrl.js
* add severity column in policy list page

Author: Zhao, Qingwen <qingwzhao@apache.org>

Closes #894 from qingwen220/EAGLE-978.
2 files changed