This properly reimplements the fix, only changing the display strings
sent to native dialog, and never modifying the filter names as seen
by LibreOffice code.

Change-Id: Iee5f09acd6b12c0ba8b7568b16f8ab07821006ee
Reviewed-on: https://gerrit.libreoffice.org/64656
Tested-by: Jenkins
Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Reviewed-on: https://gerrit.libreoffice.org/64840