unzip: Sync with NetBSD upstream.

• Ignore malformed directory entries as created by Dropbox ("/"). (rev 1.24)
• Use libarchive 3.x interface: check result for archive_read_free() and don't call archive_read_close manually. (rev 1.23)
• Always overwrite symlinks on extraction, ever if they're newer than entries in archive.
• Use getline() rather than getdelim().

PR: 231827
Submitted by: ak
Reviewed by: mm
Obtained from: NetBSD
MFC after: 2 weeks