* Add withCategories HOC and show API errors in Product Category Control
* Create withAttributes HOC and display errors in Product Attribute Control
* Refactor formatError so it handles JS errors and API errors
* Rename 'onSelectAttribute' with 'onExpandAttribute'
* Add and update tests
* Fix error in product attributes endpoint
* Refactor ProductCategoryControl into a functional component
* Refactor ProductAttributeControl into a functional component
* Refactor formatError to use a 'message' and 'type' properties
* Replace enzyme with TestRenderer
* Fix formatErrors doctype format
* Rename 'frontend' error type to 'general'
Albert Juhé Lluveras