Remove useless sort on dc:created in the workflow cleaner

The query used to get the finished workflows in DocumentRoutingServiceImpl#WfCleaner uses a sort on the dc:created field. This sort seems to be useless and can consume a lot of memory if the cleaner is run against a database which contains many terminated workflows.

Another tiny improvement? Replace

(ecm:currentLifeCycleState = 'done' OR ecm:currentLifeCycleState = 'canceled')

by

ecm:currentLifeCycleState IN ('done', 'canceled')