[BUG] UnixUserDefinedFileAttributeView::list() is always empty because BSD extattr_list_fd and Linux flistxattr are not interchangeable

From: Reinhard Pointner <reinhard.pointner_at_gmail.com>
Date: Tue, 22 Aug 2023 13:51:35 UTC
I have added links and explanation to the original commit that added
support for xattr get / set but only adds incorrect (rather incomplete)
support for xattr list: