refactor: reorganize crate hierarchy

fix/benches/utils.rs

@@ -1,8 +1,8 @@
 #![allow(dead_code)]
 
 use fix::Evaluator;
-use fix_common::Value;
 use fix_error::{Result, Source};
+use fix_lang::Value;
 
 pub fn eval(expr: &str) -> Value {
     Evaluator::new()