Suppress service roads at certain zooms (#1192)

Fixes #1191

This PR suppresses `highway=service` at zoom 12, where it is not a useful level of detail.  This makes OpenMapTiles consistent with openstreetmap-carto, which does not begin showing `highway=service` until raster zoom 14 / vector zoom 13.

Additionally, this PR suppresses `highway=service` + `service=parking_aisle` / `service=driveway` from zooms 12-13, as this detail is excessive below zoom 14.  As a point of comparison, openstreetmap-carto does not begin showing `service=parking_aisle` / `service=driveway` until raster zoom 16 (vector zoom 15).

layers/transportation/mapping.yaml

@@ -232,6 +232,9 @@ tables:
       - platform
       man_made:
       - pier
+      service:
+      - driveway
+      - parking_aisle
 
 # etldoc: imposm3 -> osm_railway_linestring
   railway_linestring:
@@ -362,6 +365,7 @@ tables:
       type: bool
     - *public_transport
     - *man_made
+    - *service
     mapping:
       highway:
       - path

layers/transportation/transportation.sql

@@ -360,7 +360,7 @@ FROM (
          WHERE NOT is_area
            AND (
                      zoom_level = 12 AND (
-                             highway_class(highway, public_transport, construction) NOT IN ('track', 'path', 'minor')
+                             highway_class(highway, public_transport, construction) NOT IN ('track', 'path', 'minor', 'service')
                          OR highway IN ('unclassified', 'residential')
                      ) AND man_made <> 'pier'
                  OR zoom_level = 13
@@ -370,6 +370,7 @@ FROM (
                             OR
                                     man_made = 'pier' AND NOT ST_IsClosed(geometry)
                         )
+                        AND service NOT IN ('driveway', 'parking_aisle')
                  OR zoom_level >= 14
                          AND (
                             man_made <> 'pier'