New field: Printed Serial Number

When using FusionInvetiry to update assets information, the "Serial number" information of the device is sometimes different from the serial number printed on the device itself. (ref: https://github.com/fusioninventory/fusioninventory-for-glpi/issues/2857#issuecomment-528764751 )

The solution will be to add another field, called for example "Printed Serial Number", and use it for write the serial number writed on the device. Serial Number will be used only for fusioninventory.