Change PositionId validation check from ASCII to UTF-8 (#3105)

Author: Osub

crates/model/src/identifiers/position_id.rs

@@ -20,7 +20,7 @@ use std::{
     hash::Hash,
 };
 
-use nautilus_core::correctness::{FAILED, check_valid_string_ascii};
+use nautilus_core::correctness::{FAILED, check_valid_string_utf8};
 use ustr::Ustr;
 
 /// Represents a valid position ID.
@@ -44,7 +44,7 @@ impl PositionId {
     /// PyO3 requires a `Result` type for proper error handling and stacktrace printing in Python.
     pub fn new_checked<T: AsRef<str>>(value: T) -> anyhow::Result<Self> {
         let value = value.as_ref();
-        check_valid_string_ascii(value, stringify!(value))?;
+        check_valid_string_utf8(value, stringify!(value))?;
         Ok(Self(Ustr::from(value)))
     }