As a followup to rB9267e6275cc9 I have tried my hand at editing the message passed to the `ModuleNotFoundError` exception which is raised when failing to enable an Addon module from a directory containing a '.'
This has the side benefit of addressing T65360 as per @lichtwerk's comment:
> (...) to check inside the .zip if we would find offending package names (...) and tell the user that the installation failed.
**Original exception message:**
**Modified exception message:**