Tar files created from the current directory (e.g. tar -czf archive.tar.gz .)
produce entries prefixed with "./". When extracting, rclone's character
encoding replaces the "." with a full-width dot (U+FF0E), creating a
spurious directory instead of merging into the destination root.
Strip the leading "./" from NameInArchive before processing. Only "./"
is stripped specifically to avoid enabling path traversal attacks via
"../".
Fixes#9168