for getting and setting the window state, work on the toplevel m_pWindow. Leave
the "geometry" alone as its for the purpose of the current known size of the
toplevel window contents

Change-Id: Idf701aacf4aed4eefbca1bc1ebebaf38d1c82e27
Reviewed-on: https://gerrit.libreoffice.org/20397Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>
(cherry picked from commit 7242ed05)