fix std help (#12943)

# Description
Fixes: #12941

~~The issue is cause by some columns(is_builtin, is_plugin, is_custom,
is_keyword) are removed in #10023~~
Edit: I'm wrong

# Tests + Formatting
Added one test for `std help`

crates/nu-std/tests/test_help.nu

@@ -0,0 +1,9 @@
+use std assert
+use std help
+
+#[test]
+def show_help_on_commands [] {
+    let help_result = (help alias)
+    assert ("item not found" not-in $help_result)
+}
+