cl-structures: Rename the deprecated "intern pool" (lmao)

Don't deprecate it yet, though, we've got more stuff yet.

compiler/cl-typeck/src/key.rs

@@ -1,4 +1,4 @@
-use cl_structures::intern_pool::*;
+use cl_structures::deprecated_intern_pool::*;
 
 // define the index types
 make_intern_key! {

compiler/cl-typeck/src/module.rs

@@ -1,7 +1,7 @@
 //! A [Module] is a node in the Module Tree (a component of a
 //! [Project](crate::project::Project))
 use cl_ast::Sym;
-use cl_structures::intern_pool::InternKey;
+use cl_structures::deprecated_intern_pool::InternKey;
 
 use crate::key::DefID;
 use std::collections::HashMap;

compiler/cl-typeck/src/project.rs

@@ -6,7 +6,7 @@ use crate::{
     path::Path,
 };
 use cl_ast::{Identifier, PathPart, TyFn, TyKind, TyRef, TyTuple, Visibility};
-use cl_structures::intern_pool::Pool;
+use cl_structures::deprecated_intern_pool::Pool;
 use std::{
     collections::HashMap,
     ops::{Index, IndexMut},