Incorrect katakana in Nihongo channel folder names

[rusq]

Describe the bug Slack export for JPN contains channel folder names in hankaku, while it should be zenkaku as per this article.

The channel names for attachments, however, are in zenkaku.

This issue was initially mentioned in this discussion post

When the channel name contains Japanese full-width katakana characters, the directory name to save the slack message data (eg. 2022-10-10.json) will be half-width katakana with using slackdump. Attachments are saved in correct full-width katakana directories.