feat(nix-daemon): Implement client handler. r/8907

This change includes only the basic nix handshake protocol handling and
sets up a client session. The only supported operation at this point is
SetOptions.

Additional operations will be implemented in subsequent cls.

Change-Id: I3eccd9e0ceb270c3865929543c702f1491768852
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12743
Autosubmit: Vladimir Kryachko <v.kryachko@gmail.com>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
Reviewed-by: edef <edef@edef.eu>
Reviewed-by: Brian Olsen <me@griff.name>

0 files changed, 0 insertions, 0 deletions