This commit refactors the formatting and structure of the reversal method for improved readability.
Additionally, it removes an unnecessary exception in the 'setCustomer' method.

This commit also fixes the customer user settings in various methods in the order class. Now,
whenever a customer is set or removed, the related articles will correctly update their user status.

This commit fixes the errors arising from non-existing classes in the AbstractOrder.php

Changes include:
- Added a comment on the shipping validation
- Corrected type declaration in the reversal function signature to include the possibility of the
parameter being null.
- Checked for the existence of ShippingStatus and ShippingEntry classes before attempting to get
Shipping status and Shipping Ids, respectively. This prevents errors if these classes do not exist.

Related: #172

Changes include:
- Modified code formatting to improve readability and conform to best coding practices.
- Updated type declarations using pipe (|) operator to indicate variable can hold multiple types.
- Adjusted the spacing around the pipe operator in type declarations for improved readability.

Updated AbstractOrder.php to return null instead of false in getShippingStatus() when the shipping
status is not set. This makes the method's behaviour more consistent.

Updated Search.php to add a condition check for class existence before retrieving shipping status.
This ensures that the code will not fail if the class is not defined.

Modified DataLayer.php to add a condition check for class existence before retrieving shipping.

Added @phpstan-ignore-next-line in Utils.php to silence phpstan for the next line of code.

Related: #172

Updated the `getCustomerFiles` method signature in `AbstractOrder.php` to accept an optional
boolean parameter `$parsing`. Method can now be customized to return parsed file information or raw
data.

If the global process id does not exist, the order takes its own hash and starts the erp process