This commit fixes all 1533 PHPCS errors that PHPCBF can fix automatically in the tests/ directory. Before this change there was a total of 3106 PHPCS errors in the WooCommerce repository and now there is 1573 errors.
* Fix up some comments to match other comments in the WC code base
* Add some missing esc_* functions
* Add a gateway filter to get_customer_tokens + a test for it