* Use order item data to match attributes.
Fixes matching on products with "any x" attributes.
* Fix attribute query on variations report.
* Fix variations report item count.
* Add test coverage.
* Add changelog entry.
* Fix non-string query prop warning in SelectControl component.
* Move custom attribute retrieval to a reusable Trait.
* Ensure all custom attribute terms are included in the API response.
* Combine all terms from custom attributes.
When they're split across multiple products.
* Add new product attributes endpoint that allows searching.
Including custom attributes in the results.
* Add endpoint to fetch custom attribute values by slug.
* Add initial tests for Product Attributes endpoint.
* Test Product Attribute search.
* Fix schema/params for attribute terms endpoint.
* Add tests for custom term values endpoint.
* Add a LIMIT to the attributes query.
* Add endpoint to retrieve single attribute by slug.
Fixes the 'self' link.
Jeff Stieler