NOOP: Format all layer's SQL code (#917)

I would like to reformat all of our SQL to have a concise coding style.
This makes it far easier to understand the code for a casual contributor,
and lets us spot errors more easily.

Most importantly, it makes it much easier to grep (search) the code because it is more likely to be in the same syntax

Some key changes:
* SQL keywords are always UPPERCASE, e.g. `SELECT WHEN AS END ...`
* types, variables, aliases, and field names (identifiers) are always lower case
* `LANGUAGE 'plpgsql'` is now `LANGUAGE plpgsql` (no quotes)
* a few minor spacing/semicolon cleanups

P.S. Per @TomPohys request, `TABLE` is spelled using upper case despite being a type for consistency with PG Docs. Same for `LANGUAGE SQL` vs `LANGUAGE plpgsql`.

layers/waterway/update_waterway_linestring.sql

@@ -1,36 +1,38 @@
 DROP TRIGGER IF EXISTS trigger_flag ON osm_waterway_linestring;
 DROP TRIGGER IF EXISTS trigger_refresh ON osm_waterway_linestring;
 
-DO $$
-BEGIN
-  update osm_waterway_linestring
-      SET tags = update_tags(tags, geometry);
+DO
+$$
+    BEGIN
+        UPDATE osm_waterway_linestring
+        SET tags = update_tags(tags, geometry);
 
-  update osm_waterway_linestring_gen1
-      SET tags = update_tags(tags, geometry);
+        UPDATE osm_waterway_linestring_gen1
+        SET tags = update_tags(tags, geometry);
 
-  update osm_waterway_linestring_gen2
-      SET tags = update_tags(tags, geometry);
+        UPDATE osm_waterway_linestring_gen2
+        SET tags = update_tags(tags, geometry);
 
-  update osm_waterway_linestring_gen3
-      SET tags = update_tags(tags, geometry);
-END $$;
+        UPDATE osm_waterway_linestring_gen3
+        SET tags = update_tags(tags, geometry);
+    END
+$$;
 
 
 -- Handle updates
 
 CREATE SCHEMA IF NOT EXISTS waterway_linestring;
 CREATE OR REPLACE FUNCTION waterway_linestring.refresh() RETURNS trigger AS
-  $BODY$
-  BEGIN
---     RAISE NOTICE 'Refresh waterway_linestring %', NEW.osm_id;
+$$
+BEGIN
+    --     RAISE NOTICE 'Refresh waterway_linestring %', NEW.osm_id;
     NEW.tags = update_tags(NEW.tags, NEW.geometry);
     RETURN NEW;
-  END;
-  $BODY$
-language plpgsql;
+END;
+$$ LANGUAGE plpgsql;
 
 CREATE TRIGGER trigger_refresh
-    BEFORE INSERT OR UPDATE ON osm_waterway_linestring
+    BEFORE INSERT OR UPDATE
+    ON osm_waterway_linestring
     FOR EACH ROW
-    EXECUTE PROCEDURE waterway_linestring.refresh();
+EXECUTE PROCEDURE waterway_linestring.refresh();