* fix(eventstore): prevent allocation of filtered events
Directly reduce each event obtained from a sql.Rows scan,
so that we do not have to allocate all events in a slice.
* reinstate the mutex as RWMutex
* scan data directly
* add todos
* fix(writemodels): add reduce of parent
* test: remove comment
* update comments
---------
Co-authored-by: adlerhurst <silvan.reusser@gmail.com>
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.
