[Bug]: quantityScale may be null in case of setting the price info quantity

[AlternateIf]

Expected behavior

Upon not passing a quantity scale it's default function value (null) should not cause an error

Actual behavior

quantity scale being null causes an error

Steps to reproduce

https://github.com/pimcore/ecommerce-framework-bundle/blob/1.x/src/PriceSystem/AbstractPriceSystem.php#L56 allows quantityScale to be null but https://github.com/pimcore/ecommerce-framework-bundle/blob/1.x/src/PriceSystem/AbstractPriceInfo.php#L44 expects it to be string or int. this causes an error (https://github.com/pimcore/ecommerce-framework-bundle/blob/1.x/src/PriceSystem/AbstractPriceSystem.php#L61)

[github-actions]

Thanks a lot for reporting the issue. We did not consider the issue as "Pimcore:Priority", "Pimcore:ToDo" or "Pimcore:Backlog", so we're not going to work on that anytime soon. Please create a pull request to fix the issue if this is a bug report. We'll then review it as quickly as possible. If you're interested in contributing a feature, please contact us first here before creating a pull request. We'll then decide whether we'd accept it or not. Thanks for your understanding.