Replace with UNO3_GETIMPLEMENTATION* macros.
Replace single usage of IMPL_XUNOTUNNEL_MINIMAL with it's body.

Change-Id: I7d4ad76399b999ebb2178ecf57edcf6bd2aa6c3e
Reviewed-on: https://gerrit.libreoffice.org/73424
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>