Create the objects on offer to Automation clients lazily

It would be silly to create the ooo.vba.word.XApplication in every
LibreOffice instance, even if no Writer functionality was going to be
used at all in that process.

I did not have to do what the old FIXME said, "make Application a
proper service", whatever that means.

Change-Id: I02a0ceb6290012b4bb6afacadc03871feaf57406
Reviewed-on: https://gerrit.libreoffice.org/55005Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tor Lillqvist <tml@collabora.com>