add unknown addr:place to address output

add unknown addr:place to address output

When a POI has no addr:street but an addr:place that is not
contained in the name list of the parent place, then remember
this situation and merge the content of addr:place into the
address output.

We don't need to care about translations in this case because
it is obvious that no object with translations exists if the
parent isn't the object named in addr:place.