Brunnel changes in transportation and transportation_name layers (#1027)

https://github.com/openmaptiles/openmaptiles/issues/999

- Point 1 solved only partially - there is `brunnel` value added into zooms 9, 10, 11. For zooms 8 and smaller it would need change in osm_transportation_merge_ tables - I am going to try it but maybe its SQL costs will be to high.

- Point 2 solved.

layers/transportation/layer.sql

@@ -220,9 +220,9 @@ FROM (
                 NULL AS shipway,
                 NULL AS public_transport,
                 NULL AS service,
-                NULL::boolean AS is_bridge,
-                NULL::boolean AS is_tunnel,
-                NULL::boolean AS is_ford,
+                is_bridge,
+                is_tunnel,
+                is_ford,
                 NULL::boolean AS is_ramp,
                 NULL::int AS is_oneway,
                 NULL AS man_made,
@@ -250,9 +250,9 @@ FROM (
                 NULL AS shipway,
                 NULL AS public_transport,
                 NULL AS service,
-                NULL::boolean AS is_bridge,
-                NULL::boolean AS is_tunnel,
-                NULL::boolean AS is_ford,
+                is_bridge,
+                is_tunnel,
+                is_ford,
                 NULL::boolean AS is_ramp,
                 NULL::int AS is_oneway,
                 NULL AS man_made,