Changed Req. Line behavior in cases where it was not possible to change to the Purchase UoM

The behavior is now changed slightly to support cases where the items were not available in the req. worksheet before:

The following scenarios are now supported:

• Change to Purch. Unit of Measure is possible (or not necessary) = Works like before
• Change to Purch. Unit of Measure does not work and Quantity is Zero. This is were the logic is now changed. There are two options:
• If the calculation is the same (for example both are m³ UoM's with same factors and rounding) = It is possible to use the quantity that was set up in the SKU
• If the calculation is different = In this case, the line will stay as Base UoM. This way the demand is visible, but it has to be changed to the Purch UoM manually as soon as the specifications are defined and it is possible to change the UoM.