Fix #60665: call to empty() on NULL result using PDO::FETCH_LAZY returns false

Fix #60665: call to empty() on NULL result using PDO::FETCH_LAZY returns false

The has_property handler only checked whether a respective column name
exists, but neither whether the column value is set, nor whether it is
empty, respectively. We fix that to match the behavior of POD:FETCH_OBJ in
particular and PHP in general.