Update Service Order with Expected Completion Date

Current behaviour: OSOM periodically checks for active services to terminate (condition: endDate < now)

Currently, if someone wants to terminate all the Services associated with a Service Order, will have to modify the property "endDate" of all supporting CFS separately. (CFSs then propagate this to their children RFSs)

Proposal: By updating a Service Order with a new "expectedCompletionDate", this should propagate the same value to every supporting service's "endDate"