Additional Product Metadata fields in Ecommerce Template

[VMRuiz]

It would be nice to pass some metadata fields to indicate how a Product item was extracted by the Ecommerce template.
For example:

• Listing URL - Indicating the listing page where the product was found
• Rank - Indicate item position relative to others on the listing page
• Page Number - For websites with pagination, the number of the page

Of course, there are some clarifications that would be required like:

• For websites with pagination, does Listing URL points to the first page or the specific page number where the product was found
• Do we keep rank across pagination or does it restart on every page?

[BurnzZ]

A similar proposal in zytedata/zyte-common-items#97 with the intent of adding additional context or information for the links.