feat(tvix/nix-compat): have StorePath accept bytes

The primary constructor for this is now from_bytes, from_string is
simply calling .as_bytes() on the string, passing it along.

The InvalidName error now contains a Vec<u8>, to encode the invalid name
(which might not be a string anymore).

from_absolute_path now accepts a &[u8] (even though we might want to
make this a OSString of some sort).

StorePath::validate_name has been degraded to a pub(crate) function.
It's still used in src/derivation, even though it probably shouldn't at
all - that cleanup is left for cl/8412 though.

Change-Id: I6b4e62a6fa5c4bec13b535279e73444f0b83ad35
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8973
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>

tvix/store/src/fuse/mod.rs

@@ -19,6 +19,7 @@ use crate::{
 use fuser::{FileAttr, ReplyAttr, Request};
 use nix_compat::store_path::StorePath;
 use std::io::Read;
+use std::str::FromStr;
 use std::sync::Arc;
 use std::{collections::HashMap, time::Duration};
 use tracing::{debug, info_span, warn};
@@ -99,7 +100,7 @@ impl FUSE {
     ) -> Result<Option<(u64, Arc<InodeData>)>, Error> {
         // parse the name into a [StorePath].
         let store_path = if let Some(name) = name.to_str() {
-            match StorePath::from_string(name) {
+            match StorePath::from_str(name) {
                 Ok(store_path) => store_path,
                 Err(e) => {
                     debug!(e=?e, "unable to parse as store path");