TRUNK-4173: Refactor OrderService.getOrders

**Tasks:**
- [x] Replace the current OrderService.getOrders(..) and other methods in the OrderService interface
- [ ] Implement the changed methods in the OrderServiceImpl
- [ ] Remove @Ignore from ``handle_shouldVoidTheOrdersEncountersAndObservationsAssociatedWithThePatient()``, and update the test to pass by excluding voided orders.

*This branch will be rebased upon merging TRUNK-4287 #731 or something similar*