* Sync refunds on order sync
* Separate order and refund class extensions
* Add customer functions to order and refund classes
* Change products store to work with refund amounts
* Return early for refunds in coupon data store
* Allow refund processing in tax data store
* Remove unused refund amounts from tables and data stores
* Change order counts to parse out refund entries
* Include refunded orders in default queried statuses
* Only process order number filter on shop order post types
* Extract shared order and refund methods to trait
* Fix renamed schedule_single_order_import method
* Bump PHP and WP version requirements