fdo#60698: Merge fastsax and sax_shared into expwrap

Change-Id: I6f8c6827c00db50184a46f39968f882b944d18d4
Reviewed-on: https://gerrit.libreoffice.org/6967
Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: LibreOffice gerrit bot <gerrit@libreoffice.org>