fixes https://github.com/TryGhost/Team/issues/2200
When zipping a folder that contains files with UTF-8 characters in the filename, using the MacOS Archive Utility, the resulting zip will be missing some UTF-8 configuration bit. This breaks the unzipper, causing it to decode the filenames using the wrong encodign.
When the file names are long, and become longer than the length allowed by the OS, an ENAMETOOLONG error is thrown. This error is not handled by the importer, and causes the import to fail.
This adds a specific check for this error so we can show a clear error message to the user, that helps them to resolve the issue. We are currently unable to fix the issue on our side, because of a lack of well supported zip libraries for node.
refs: https://github.com/TryGhost/Team/issues/1121
- We've decided on one preferred message for unexpected errors
- We want to use this everywhere where we don't know what to display
- We now have a GENERIC_ERROR_MESSAGE constant that we should use
