Remove the requirement of dispensing event in Drug Orders

In the Drug Orders, the default requirements include to have dispensing event and sign off by provider/user. If not, the prescription can only be saved as draft. For our use case, our patients might get their drugs dispensed outside of the hospital so we won't know the actual dispensing event.

As a provider, I expect that the Drug Orders doesn't require the actual dispensing event at the hospital pharmacy so that I can save my prescription.