district and county fields are currently unsupported in the landmark qsparql backend

1) The landmark attributes for district and county are not yet supported. These attributes are ignored when a landmark is saved.

To reproduce:
1) Using the landmark browser save a landmark with a district.
2) Edit the landmark, observe that the district field is has not been saved.
(the landmark browser is currently missing a field for county)

Expected:
When adding a landmark using the landmark browser it is possible to add both district and county fields. And when editing a landmark after saving, it is shown that those fields have actually been saved.