fdo#83204 RTF import: handle \pard<para props> after \bkmkstart

(cherry picked from commit 8a30ba573470d59dbb0501b488f8a655b015ffd2)

Change-Id: I4f5f0f653f2ce7782ec1d1fc5ef550a21a9c1d35
Reviewed-on: https://gerrit.libreoffice.org/12527
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>