Use overlay ID for module import lookup (#4514)

* Add id to import pattern

* Finish testing importing in a block

crates/nu-command/tests/commands/mod.rs

@@ -60,6 +60,7 @@ mod str_;
 mod touch;
 mod uniq;
 mod update;
+mod use_;
 mod where_;
 #[cfg(feature = "which")]
 mod which;