refactor: reorganize crate hierarchy

fix/tests/tests/derivation.rs

@@ -1,4 +1,4 @@
-use fix_common::Value;
+use fix_lang::Value;
 
 use crate::utils::{eval_deep, eval_deep_result};
 

fix/tests/tests/io_operations.rs

@@ -1,6 +1,6 @@
 use fix::Evaluator;
-use fix_common::Value;
 use fix_error::Source;
+use fix_lang::Value;
 
 use crate::utils::{eval, eval_result};
 

fix/tests/tests/lang.rs

@@ -3,8 +3,8 @@
 use std::path::PathBuf;
 
 use fix::Evaluator;
-use fix_common::Value;
 use fix_error::{Source, SourceType};
+use fix_lang::Value;
 
 fn get_lang_dir() -> PathBuf {
     PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("tests/tests/lang")

fix/tests/tests/string_context.rs

@@ -1,5 +1,5 @@
 use fix::Evaluator;
-use fix_common::Value;
+use fix_lang::Value;
 
 use crate::utils::eval_result;
 

fix/tests/tests/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()