Need to repeat what OLE1 calls the class name in the OLE1 and RTF
wrappers, so parse our own OLE2 data during export.

Change-Id: Ic14fa648d1f78c29579bd9ba49ce6f491d4541b5
Reviewed-on: https://gerrit.libreoffice.org/51906Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Jenkins <ci@libreoffice.org>