Use WooCommerce filters/hooks instead of hardcoding include files

I’m looking into getting the plugin working with WooCommerce as a MU plugin and noticed the following code issues that would prevent an simple fix/override using WooCommerce as an MU plugin. The path for the MU plugin would simply be mu-plugin/ instead of plugin/

The following code looks like it would be unnecessary if a WooCommerce hook was used (woocommerce_get_settings_pages).

if(!class_exists('\WC_Settings_Page')){
   include_once WP_CONTENT_DIR . '/plugins/woocommerce/includes/admin/settings/class-wc-settings-page.php';
}

This is also the case with Abstract_Gateway that extends WC_Payment_Gateway.