feat(eventstore): increase parallel write capabilities (#5940)

This implementation increases parallel write capabilities of the eventstore.
Please have a look at the technical advisories: [05](https://zitadel.com/docs/support/advisory/a10005) and  [06](https://zitadel.com/docs/support/advisory/a10006).
The implementation of eventstore.push is rewritten and stored events are migrated to a new table `eventstore.events2`.
If you are using cockroach: make sure that the database user of ZITADEL has `VIEWACTIVITY` grant. This is used to query events.

internal/eventstore/v3/push.sql

@@ -0,0 +1,18 @@
+INSERT INTO eventstore.events2 (
+    instance_id
+    , "owner"
+    , aggregate_type
+    , aggregate_id
+    , revision
+
+    , creator
+    , event_type
+    , payload
+    , "sequence"
+    , created_at
+
+    , "position"
+    , in_tx_order
+) VALUES
+    %s
+RETURNING created_at, "position";