/vsizip/: use the extented field for UTF-8 filenames to retrieve UTF-8 filenames when the base filename field contains CP437 filename (#5361)

git-svn-id: https://svn.osgeo.org/gdal/trunk@26882 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into trunk_travis_macosx