BUGFIX: Ignore duplicate route concurrencies (#1233)

While troubleshooting #1230, I discovered that there were cases where a way was a member of the same route relation more than once, such as: https://www.openstreetmap.org/way/17439235

<img src="https://user-images.githubusercontent.com/3254090/133726616-acd01332-343e-4930-ad3d-1fb3c3190a4c.png" width=280/>

This segment would end up showing duplicate highway shields in a rendered style, which is not desirable.  While I personally think this style of tagging is wrong, it's a relatively easy fix to remove those duplicates.  This PR replaces `ROW_NUMBER()` with `DENSE_RANK()` in the concurrency index generation code and adds a `DISTINCT` constraint on the concurrency join to handle multiple member rows with the same concurrency index.

Since I was in this file, I also fixed the copy/paste error in generating the route names.

Screenshot from database showing correct mapping:
![image](https://user-images.githubusercontent.com/3254090/133725554-1aa5dbbc-59a8-4674-a446-b92adb96c2a1.png)

layers/transportation/update_route_member.sql

@@ -85,7 +85,7 @@ 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
+    DENSE_RANK() 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;