refactor(tvix/nix-compat): move worker_protocol into nix_daemon mod

This doesn't have much to do with the plain "wire" format, it's merely
one user of it.

Also, use the more "public" `wire::` API to read/write bytes, strings,
bools and u64s.

Change-Id: I98dddcc3004dfde7a0c009958fe84a840f77b188
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11390
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Reviewed-by: Brian Olsen <me@griff.name>

users/picnoir/tvix-daemon/src/main.rs

@@ -3,10 +3,8 @@ use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio_listener::{self, SystemOptions, UserOptions};
 use tracing::{debug, error, info, instrument, Level};
 
-use nix_compat::wire::{
-    self,
-    worker_protocol::{self, server_handshake_client, ClientSettings, Trust},
-};
+use nix_compat::wire;
+use nix_compat::worker_protocol::{self, server_handshake_client, ClientSettings, Trust};
 
 #[derive(Parser, Debug)]
 struct Cli {