Clients should now use these APIs to search for text in the
widget, rather than executing UNO commands directly on the
widget. This allows searching for text in the widget in view-only
mode too.

Change-Id: I013b6f96e69a634ec33367394d39c0f645a4994d
Reviewed-on: https://gerrit.libreoffice.org/20488Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: David Tardon <dtardon@redhat.com>