Improved functionality of the RFP

To download the supplier's price lists, the ability to check availability based on the condition specified in the field “Consider that the product is not in stock if the text is in stock” has been improved Works like this: We ship the price list, which marks the products in stock and out of stock. In the corresponding price field, we fix the condition with the field value, under which the product will be marked as out of stock. All other products are shipped in stock. If a product is not listed, we assume that it is out of stock.