add sql to run after tables have been imported

* materialized view for osm_buildings
use materialized view instead of buildings query
add 110m and 50m natural earth land datasets
update import to add ne 50m/110m land tables
updated earth queries for lower zoom levels
update vtm buildings query

Needed to add building and building_part columns to the osm_buildings
materialized view.
use way_area where possible
use water-z4 queries instead of z6
speed up land use queries with materialized view
specific geometry tolerances for land use zooms

Update the land use materialized view to have specific geometry
simplifications at each zoom level.
simplify building ways for zoom levels