Create all service users with forced path

as discussed with kpauls and Sc0rpic0m in private conversation the converter should have the ability to create all service users with a forced path (not just when principal-based access control setup is enforced).
with this additional flexibility present we can safely run the converter repeatedly on an existing repository having --enforce-principal-based-supported-path configuration enabled and disabled as it would not only move service users to the supported path but also restore the original path as specified in repoinit and content-package if executed again with the configuration disabled.