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/cockroach/create_index.sql

@@ -0,0 +1,8 @@
+CREATE INDEX IF NOT EXISTS ca_fill_idx ON eventstore.events (
+    event_sequence DESC
+    , instance_id
+) STORING (
+    id
+    , creation_date
+    , created_at
+) WHERE created_at IS NULL;