Added fields Franco Order Amount and Franco Order Volume for vendors to store information about free delivery

The inclusion of "Franco Order Amount" and "Franco Order Volume" fields offers users a practical tool for efficiently monitoring orders eligible for free shipping, aiding in logistics management without unnecessary complexity.

Both fields are added to the vendor card, these fields are just for information purposes and there is business logic behind it. Also in the vendor details factbox and the planning factbox the fields are visible.

It is recommended to set the "Franco Order Amount" in the currency of the vendor, to be able to easily compare amounts in purchase with the franco order amount.