* Rename RecordStatesAsync to Record
* Rename QueryStates to Query
* Implement fanout writes
* Implement primary queries
* Simplify error joining
* Add test for query path
* Add tests for writes and error propagation
* Allow fanout backend to be configured
* Touch up log messages and config validation
* Consistent documentation for all backend structs
* Parse and normalize backend names more consistently against an enum
* Touch-ups to documentation
* Improve clarity around multi-record blocking
* Keep primary and secondaries more distinct
* Rename fanout backend to multiple backend
* Simplify config keys for multi backend mode
