PreviewJob: Use kio-fuse for remote files
Previously, PreviewJob copied the remote file to a local temporary file if a thumbnail plugin requires access to a local file path. This makes it infeasible to preview large files, like videos.
This MR makes PreviewJob use kio-fuse to expose local file paths to these plugins for otherwise remote files, similar to how DesktopExecParser does it for non-KIO applications.
Co-authored-by: Andrew Gunnerson
Edited by John Chadwick