Get Catalog Summary
Returns a lightweight inventory summary from the BigCommerce Catalog.
The inventory summary includes:
* "inventory_count"
* "variant_count"
* "inventory_value"
* "highest_variant_price"
* "average_variant_price"
* "lowest_variant_price"
* "oldest_variant_date"
* "newest_variant_date"
* "primary_category_id"
* "primary_category_name"