refactor(tvix/nix-compat): reorganize wire and bytes

Move everything bytes-related into its own module, and re-export
both bytes and primitive in a flat space from wire/mod.rs.

Expose this if a `wire` feature flag is set. We only have `async` stuff
in here.

Change-Id: Ia4ce4791f13a5759901cc9d6ce6bd6bbcca587c7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11389
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
Reviewed-by: Brian Olsen <me@griff.name>

users/picnoir/tvix-daemon/Cargo.lock

@@ -441,12 +441,6 @@ version = "0.3.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dfc6580bb841c5a68e9ef15c77ccc837b40a7504914d52e47b8b0e9bbda25a1d"
 
-[[package]]
-name = "futures-io"
-version = "0.3.30"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a44623e20b9681a318efdd71c299b6b222ed6f231972bfe2f224ebad6311f0c1"
-
 [[package]]
 name = "futures-macro"
 version = "0.3.30"
@@ -477,10 +471,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3d6401deb83407ab3da39eba7e33987a73c3df0c82b4bb5813ee871c19c41d48"
 dependencies = [
  "futures-core",
- "futures-io",
  "futures-macro",
  "futures-task",
- "memchr",
  "pin-project-lite",
  "pin-utils",
  "slab",
@@ -753,7 +745,6 @@ dependencies = [
  "ed25519",
  "ed25519-dalek",
  "enum-primitive-derive",
- "futures-util",
  "glob",
  "nom",
  "num-traits",