Order Service should always set autoExpireDate if duration is set

The current implementation of Order Service leaves the setting of autoExpireDate to each DosingInstructions implementation, and does not ensure that autoExpireDate is set based on duration if supplied.

As discussed here:  https://talk.openmrs.org/t/duration-and-auto-expire-date-on-orders/32006/2 this should be changed, so that autoExpireDate is automatically set by the Order Service on any Drug Order regardless of dosing instructions, if it is not already set.

burke FYI