Use osm_id as feature id for building layer (#827)

Change the feature_id of objects in the tiles from arbitrary number to osm_id.

From discussion here #725 (comment)

Note the multiploygon building are load with negative relation osm_id. But the use in feature_id do an overflow (eg -7980888 -> 18446744073701570000). We can keep as is or not.

No stats done for yet. Trying to let the CI do it.

layers/building/building.yaml

@@ -5,7 +5,11 @@ layer:
       this is welcomed.
   buffer_size: 4
   datasource:
-    query: (SELECT geometry, render_height, render_min_height, colour, hide_3d FROM layer_building(!bbox!, z(!scale_denominator!))) AS t
+    geometry_field: geometry
+    key_field: osm_id
+    key_field_as_attribute: no
+    srid: 900913
+    query: (SELECT osm_id, geometry, render_height, render_min_height, colour, hide_3d FROM layer_building(!bbox!, z(!scale_denominator!))) AS t
   fields:
     render_height: |
         An approximated height from levels and height of the building or building:part after the method of Paul Norman in [OSM Clear](https://github.com/ClearTables/osm-clear). For future 3D rendering of buildings.