This adds support for client authentication using TLS certificates when making requests to a remote backend.

Summary of changes

- Added new configuration options for client certificate and private key
- Configured demo nginz to require client certificates
- Read client certificate on federator startup
- Use client certificate when creating a GRPC client
- Upgrade haskell packages tls and cryptonite
- Add script to serve helm charts in a repository running at http://localhost:4001 

Co-authored-by: jschaul <jschaul@users.noreply.github.com>
Co-authored-by: Akshay Mankar <akshay@wire.com>