* refactor all draft order functionality to be in it’s own class and feature gate it.
* move and fix tests for draft order deletes
* add test to ensure only draft orders are deleted
* implement review feedback and assert valid results before deleting
* update tests
* doh method can’t be protected
* fix conditional for removing scheduled action
* switch to use Woo Core function for catching the exception
* add tests for error handling.
* use `$wpdb->prepare` and remove temp group on test
Darren Ethier