Always create the "." UDSEntry

Summary:
The smb_kio plugin does not create the "." UDSEntry,
relying on the underlying KIO infrastructure to create a default one.

This patch ensures that the UDSEntry is always created with proper access permissions.

CCBUG: 376344

Reviewers: elvisangelaccio

Differential Revision: https://phabricator.kde.org/D6616