Improve compliance with a Metrc-compliant POS for Maryland that tracks product quantities as a result of the POS

https://wiki.robotrage.pro/index.php/Maryland_Seed-to-Sale_POS:_Keeping_Packages,_Sales,_and_Transfers_Aligned

Improve compliance with a Metrc-compliant POS for Maryland that tracks product amounts because of the POS and keeps METRC stock aligned with each transaction.