Add network to transport layer (#1158)

Closes #1153 

This PR populates the existing `network_type` field in the route table with highway route network information, using the most important value in cases of concurrencies.  In order to expose this value, two files `network_type.sql` and `update_route_member.sql` were moved from the `transportation_name` layer to the `transportation` layer.

Below is a representative zoom level 6 with motorways only shown for `us-interstate` network types.  This sample was generated from this PR using a [custom branch](https://github.com/ZeLonewolf/openstreetmap-americana/tree/selective-highway-zoom) of openstreetmap-americana.  This provides a simplified rendering of the highway network which excludes many minor motorway roads and sections.
![image](https://user-images.githubusercontent.com/3254090/126420985-c380b54b-a991-4a7c-a4c1-40a5cf5ec6b0.png)

Below is zoom level 6 on the current [openstreetmap-americana](https://zelonewolf.github.io/openstreetmap-americana/#6/42.148/-73.712).  Notice the many additional stubs, motorway islands, and minor routes which are present.  Instead of rendering `highway=trunk` to make this network look nice, we can instead suppress non-interstate roads and withhold motorway+trunk rendering to a closer zoom:
![image](https://user-images.githubusercontent.com/3254090/126421148-71e780ec-991d-4e38-a82a-85015b349e97.png)

layers/transportation/update_route_member.sql

@@ -0,0 +1,97 @@
+CREATE TABLE IF NOT EXISTS ne_10m_admin_0_bg_buffer AS
+SELECT ST_Buffer(geometry, 10000)
+FROM ne_10m_admin_0_countries
+WHERE iso_a2 = 'GB';
+
+CREATE OR REPLACE VIEW gbr_route_members_view AS
+SELECT 0,
+       osm_id,
+       substring(ref FROM E'^[AM][0-9AM()]+'),
+       CASE WHEN highway = 'motorway' THEN 'omt-gb-motorway' ELSE 'omt-gb-trunk' END
+FROM osm_highway_linestring
+WHERE length(ref) > 0
+  AND ST_Intersects(geometry, (SELECT * FROM ne_10m_admin_0_bg_buffer))
+  AND highway IN ('motorway', 'trunk')
+;
+-- Create GBR relations (so we can use it in the same way as other relations)
+DELETE
+FROM osm_route_member
+WHERE network IN ('omt-gb-motorway', 'omt-gb-trunk');
+-- etldoc:  osm_highway_linestring ->  osm_route_member
+INSERT INTO osm_route_member (osm_id, member, ref, network)
+SELECT *
+FROM gbr_route_members_view;
+
+CREATE OR REPLACE FUNCTION osm_route_member_network_type(network text) RETURNS route_network_type AS
+$$
+SELECT CASE
+           WHEN network = 'US:I' THEN 'us-interstate'::route_network_type
+           WHEN network = 'US:US' THEN 'us-highway'::route_network_type
+           WHEN network LIKE 'US:__' THEN 'us-state'::route_network_type
+           -- https://en.wikipedia.org/wiki/Trans-Canada_Highway
+           WHEN network LIKE 'CA:transcanada%' THEN 'ca-transcanada'::route_network_type
+           WHEN network = 'omt-gb-motorway' THEN 'gb-motorway'::route_network_type
+           WHEN network = 'omt-gb-trunk' THEN 'gb-trunk'::route_network_type
+           END;
+$$ LANGUAGE sql IMMUTABLE
+                PARALLEL SAFE;
+
+-- etldoc:  osm_route_member ->  osm_route_member
+-- see http://wiki.openstreetmap.org/wiki/Relation:route#Road_routes
+UPDATE osm_route_member
+SET network_type = osm_route_member_network_type(network)
+WHERE network != ''
+  AND network_type IS DISTINCT FROM osm_route_member_network_type(network)
+;
+
+CREATE OR REPLACE FUNCTION update_osm_route_member() RETURNS void AS
+$$
+BEGIN
+    DELETE
+    FROM osm_route_member AS r
+        USING
+            transportation_name.network_changes AS c
+    WHERE network IN ('omt-gb-motorway', 'omt-gb-trunk')
+      AND r.osm_id = c.osm_id;
+
+    INSERT INTO osm_route_member (osm_id, member, ref, network)
+    SELECT r.*
+    FROM gbr_route_members_view AS r
+             JOIN transportation_name.network_changes AS c ON
+        r.osm_id = c.osm_id;
+
+    UPDATE
+        osm_route_member AS r
+    SET network_type = osm_route_member_network_type(network)
+    FROM transportation_name.network_changes AS c
+    WHERE network != ''
+      AND network_type IS DISTINCT FROM osm_route_member_network_type(network)
+      AND r.member = c.osm_id;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE INDEX IF NOT EXISTS osm_route_member_network_idx ON osm_route_member ("network");
+CREATE INDEX IF NOT EXISTS osm_route_member_member_idx ON osm_route_member ("member");
+CREATE INDEX IF NOT EXISTS osm_route_member_name_idx ON osm_route_member ("name");
+CREATE INDEX IF NOT EXISTS osm_route_member_ref_idx ON osm_route_member ("ref");
+
+CREATE INDEX IF NOT EXISTS osm_route_member_network_type_idx ON osm_route_member ("network_type");
+
+ALTER TABLE osm_route_member ADD COLUMN IF NOT EXISTS concurrency_index int;
+
+INSERT INTO osm_route_member (id, concurrency_index)
+  SELECT
+    id,
+    ROW_NUMBER() over (PARTITION BY member ORDER BY network_type, network, LENGTH(ref), ref) AS concurrency_index
+  FROM osm_route_member
+  ON CONFLICT (id) DO UPDATE SET concurrency_index = EXCLUDED.concurrency_index;
+
+UPDATE osm_highway_linestring hl
+  SET network = rm.network_type
+  FROM osm_route_member rm
+  WHERE hl.osm_id=rm.member AND rm.concurrency_index=1;
+
+UPDATE osm_highway_linestring_gen_z11 hl
+  SET network = rm.network_type
+  FROM osm_route_member rm
+  WHERE hl.osm_id=rm.member AND rm.concurrency_index=1;