Edit quantity when Order is re-opened

Overview
When a User wants to edit quantity on an Open order can be done in 2 ways:
1) Re-open Order(Orders goes from Open-> Pending -> Open)
2) Edit already Open Order

The scope of this story is just 1. Reopening order
When Order is re opened (Order moved from Open to Pending and then to Open), the user is allowed to edit quantity. When the order is re-opened after the edit,
For PUT Orders call, while RE-Opening an order

• check if there are more pieces than required or the location has been modified, throw an error stating that pieces need to be deleted.
• Leave the Order in pending state, if there are pieces to be deleted

When the extra pieces are to be deleted
DELETE /pieces call,

• Delete the corresponding Item, if there are no requests on the item
  • throw an error if there is an open request, and do not delete the piece or item
• If there are no items in the holding, delete the holding DB: holding may relate to other orders even if they have no items so deleting them is problematic and we will avoid it for now
• Do not delete Instance

Acceptance Criteria

• Both the API changes are made
• API tests are updated
• unit tests are updated