* Limit new MLS federation endpoints to V1

* Remove "strongly typed" Named wrapper

* Add version 0 of get-mls-clients endpoint

* Limit old MLS RPC to version 0

* Add version header to federated requests

* Propagate version header through federator

* Regenerate nix packages

* Add CHANGELOG entry

* Set latest fed API version in integration tests

* Include headers in a federator unit test