fix(setup): steps 10 and 11 (#5987)

* fix(step10): count amount of wrong_events manually

* fix(step11): create index for better performance

cmd/setup/11/11_fetch_events.sql

@@ -1 +1,12 @@
-SELECT id, creation_date FROM eventstore.events WHERE created_at IS NULL ORDER BY event_sequence DESC, instance_id LIMIT 20 FOR UPDATE
+SELECT 
+    id
+    , creation_date 
+FROM 
+    eventstore.events 
+WHERE 
+    created_at IS NULL 
+ORDER BY 
+    event_sequence DESC
+    , instance_id 
+LIMIT $1 
+FOR UPDATE