Add prelude and while macro

This commit introduces a new prelude file that defines the `while` macro
and registers it during environment bootstrapping. The `again` macro has
been updated to accept multiple arguments for its recursive call, and
several examples have been adjusted to reflect this change.
Additionally, the `MacroRegistry` in the compiler is now cloneable and
can be moved out of the `MacroExpander`.

src/integration_test.rs

@@ -267,7 +267,7 @@ mod tests {
     #[should_panic(expected = "'again' is only allowed in tail position to avoid dead code.")]
     fn test_again_non_tail_panic() {
         let env = Environment::new();
-        let source = "(do (def f (fn [x] (do (again [(- x 1)]) x))) (f 5))";
+        let source = "(do (def f (fn [x] (do (again (- x 1)) x))) (f 5))";
         // This will trigger the TCO pass which contains the validation logic
         let _ = env.run_script(source);
     }