OphTrOperationbooking_ScheduleOperation_PatientUnavailable data object, rolled into Element_OphTrOperationbooking_ScheduleOperation element and overall booking resource, tests updated.
created OphTrOperationbooking_ScheduleOperation_PatientUnavailableReason resource and tests.
made Element_OphTrOperationbooking_ScheduleOperation use auto_update_relations to set the patient unavailables.