EA-35 | D3, Hemanth | Fix revising scheduled drug order to start today

The `cloneForRevision` method  was copying the scheduled date and urgency from previous drug order. We have added code clear the scheduled date when a drug order is revised to start from today.
This will not allow clients to send their own auto expire date. Instead of setting it to null, shouldn't we just copy the auto expire date sent from client (regardless of order action and duration)?