lok: add batch mode option to load the document

lok: add batch mode option to load the document

When the LibreOffice Kit is active by default is
set to headless mode, with the flag "DialogCancelMode::Silent",
according to the documentation it should close the dialog,
but it was changed for dialog tunneling.

However the dialog tunneling is being deprecated, and
in order to not produce any regression, it will be used
temporary a new state "DialogCancelMode::LOKSilent", to disable
any dialog interactivity.

Change-Id: I3b6cce38c37f75dc1b24dda352f6caec19438ff1
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/111087
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-by: Jan Holesovsky <kendy@collabora.com>
(cherry picked from commit 5f3fbb019bd79bd57eed94e01bd2202efd9a0c06)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/111319
Tested-by: Jenkins
Reviewed-by: Henry Castro <hcastro@collabora.com>