downloading documents from the portal doesn't work

If you try to download a file via the customer portal, it does not work. A document does get downloaded but without contents. That is beacuse the CustomerPortal_DownloadFile api is using the "diplay" name of the document in the path instead of the "storedname".

E.g. the portal uses a path like this one: storage/2022/September/week1/9434_myfile.png instead of this: storage/2022/September/week1/9434_a04cb8e940b6f3a9abc9ab7cd8b96e03.png which is the real name of the file in the file system.