Add ref field to railway=derail (#2108)

Author: gy-mate

data/presets/railway/derail.json

@@ -4,7 +4,8 @@
         "vertex"
     ],
     "fields": [
-        "direction_vertex"
+        "direction_vertex",
+        "ref"
     ],
     "tags": {
         "railway": "derail"