export centroid to tokenizer

May come in handy when developping sanitizers for an area smaller
than country size.

lib-sql/functions/placex_triggers.sql

@@ -16,7 +16,9 @@ CREATE TYPE prepare_update_info AS (
   country_code TEXT,
   class TEXT,
   type TEXT,
-  linked_place_id BIGINT
+  linked_place_id BIGINT,
+  centroid_x float,
+  centroid_y float
 );
 
 -- Retrieve the data needed by the indexer for updating the place.
@@ -71,6 +73,8 @@ BEGIN
   result.type := p.type;
   result.country_code := p.country_code;
   result.rank_address := p.rank_address;
+  result.centroid_x := ST_X(p.centroid);
+  result.centroid_y := ST_Y(p.centroid);
 
   -- Names of linked places need to be merged in, so search for a linkable
   -- place already here.