Add productlistitem Adobe Analytics extension fields

## What are the schemas that are affected by the issue
https://ns.adobe.com/experience/analytics-experienceevent

## What are examples of products that are impacted by the issue
Adobe Analytics and other Adobe solutions using Analytics produced ExperienceEvents.

Start by reviewing the affected Adobe Analytics ExperienceEvent schema at https://ns.adobe.com/experience/analytics-experience and compare its product list item definitions with the requested change. The issue does not identify the fields to add or any tests; the work is done when the required product list item fields are defined in the schema and validated against the stated Adobe Analytics use case.

Written by the indexing model from the issue text.