fabric Product API

**Product**, a subset of Product Catalog endpoints, aims at making item management more efficient. They create, update, and get items, which may be individual items or collection of items (called bundles). Each item has a title, item ID, description, category, and assigned attributes. Multiple options of a given item become variants of that item. For example, a t-shirt with three sizes may have small, medium, and large variants. Each variant has its own item ID, attributes, and other data points. Each variant is nested under its parent item, allowing the different options to appear on the same product page. You can also create or update one or more item attributes and attribute groups.