Add expressway tagging to the transportation layer (#1313)

Fixes #1148 

This PR adds expressway tagging to the `transportation` layer, by setting `expressway=1` for non-motorway roads tagged `expressway=yes`, and omitting the tag otherwise.  Additionally, I've added a few unit tests to verify that the expressway tagging is being imported and updated into the intermediate tables.

Here is an example of expressway tagging on US-1 in Rhode Island, USA:

![image](https://user-images.githubusercontent.com/3254090/143501278-db3671b2-2efa-4998-bffd-9ddfec63579b.png)

tests/import/500_import-highway.osm

@@ -37,6 +37,7 @@
     <nd ref="500011" />
     <nd ref="500012" />
     <tag k="highway" v="trunk"/>
+    <tag k="expressway" v="yes"/>
     <tag k="name" v="OpenMapTiles Trunk"/>
   </way>
   <way id="5002" version="1" timestamp="2019-01-01T00:00:00Z" visible="true">

tests/test-post-import.sql

@@ -133,6 +133,13 @@ BEGIN
     INSERT INTO omt_test_failures VALUES(500, 'import', 'osm_transportation_linestring z9 import tags expected 1, got ' || cnt);
   END IF;
 
+  SELECT COUNT(*) INTO cnt FROM osm_transportation_merge_linestring_gen_z9
+    WHERE highway = 'trunk'
+      AND expressway = TRUE;
+  IF cnt < 1 THEN
+    INSERT INTO omt_test_failures VALUES(500, 'import', 'osm_transportation_linestring z9 import expressway expected >=1, got ' || cnt);
+  END IF;
+
   -- Same-named road split into 3 parts, because the middle segment is tagged toll=yes
   SELECT COUNT(*) INTO cnt FROM osm_transportation_name_linestring WHERE tags->'name' = 'OpenMapTiles Secondary 3';
   IF cnt <> 2 THEN

tests/test-post-update.sql

@@ -55,6 +55,14 @@ BEGIN
     INSERT INTO omt_test_failures VALUES(500, 'update', 'osm_transportation_linestring unsplit road count expected 1, got ' || cnt);
   END IF;
 
+  -- Verify expressway tag updated
+  SELECT COUNT(*) INTO cnt FROM osm_transportation_merge_linestring_gen_z9
+    WHERE highway = 'primary'
+      AND expressway = TRUE;
+  IF cnt < 1 THEN
+    INSERT INTO omt_test_failures VALUES(500, 'import', 'osm_transportation_linestring z9 update expressway expected >=1, got ' || cnt);
+  END IF;
+
   -- Verify tags changed
   SELECT COUNT(*) INTO cnt FROM osm_transportation_merge_linestring_gen_z9
     WHERE is_tunnel = TRUE

tests/update/500_update-highway.osc

@@ -5,6 +5,13 @@
         Change tags
   -->
   <modify>
+    <way id="5002" version="1" timestamp="2019-01-01T00:00:00Z" visible="true">
+      <nd ref="500021" />
+      <nd ref="500022" />
+      <tag k="highway" v="primary"/>
+      <tag k="expressway" v="yes"/>
+      <tag k="name" v="OpenMapTiles Primary"/>
+    </way>
     <!-- Change tags -->
     <way id="5003" version="2" timestamp="2020-01-02T00:00:00Z" visible="true">
       <nd ref="500031" />