put (so far) no-op UNO ifaces in place

Change-Id: I95394cfe05b8e3db21ddce6dfed1c1bb1d0e6381
Reviewed-on: https://gerrit.libreoffice.org/61385
Tested-by: Jenkins
Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>