Properly redirect invocations (#2070)

* Properly redirect invocations

* Don't convert with-env yet, as there's a random test failure

tests/shell/pipeline/commands/internal.rs

@@ -84,13 +84,25 @@ fn it_expansion_of_invocation() {
     assert_eq!(actual.out, "4");
 }
 
+#[test]
+fn invocation_properly_redirects() {
+    let actual = nu!(
+        cwd: ".",
+        r#"
+            echo $(nu --testbin cococo "hello") | str collect
+        "#
+    );
+
+    assert_eq!(actual.out, "hello");
+}
+
 #[test]
 fn argument_invocation() {
     let actual = nu!(
         cwd: ".",
         r#"
-                    echo "foo" | echo $(echo $it)
-            "#
+            echo "foo" | echo $(echo $it)
+        "#
     );
 
     assert_eq!(actual.out, "foo");