Change the free shipping label into applied free shipping rule title

Update the free shipping label to reflect the applied free shipping rule title.

add_filter( 'woocommerce_cart_shipping_method_full_label', function( $label, $method ) {
    if(is_object($method) && $method->method_id == 'wdr_free_shipping' && class_exists('\Wdr\App\Controllers\ManageDiscount') && class_exists('\Wdr\App\Controllers\DiscountCalculator')) {
        if (!empty(\Wdr\App\Controllers\ManageDiscount::$calculator)) {
            $calc = \Wdr\App\Controllers\ManageDiscount::$calculator;
            $applied_rules = $calc::$applied_rules;
            foreach ($applied_rules as $applied_rule) {
                if($applied_rule->rule->discount_type == 'wdr_free_shipping') {
                    $label = $applied_rule->rule->title;
                }
            }
        }
    }
    return $label;
}, 10, 2);