Previously, both Repackager and the Grade plugin used the JRE's
standard ZipOutputStream when creating a fat jar or war file. This
resulted in entry names that needed UTF-8 encoding to become
corrupted.

This commit updates both to use Commons Compress'
ZipArchiveOutputStream and to configure the stream's encoding and
each entry's Unix mode. This ensures that names are encoded using
UTF-8 and can be read back in correctly by common zip tools.

Closes gh-9405