Track call arguments in a single list (#5125)

* Initial implementation of ordered call args

* Run cargo fmt

* Fix some clippy lints

* Add positional len and nth

* Cargo fmt

* Remove more old nth calls

* Good ole rustfmt

* Add named len

Co-authored-by: Hristo Filaretov <h.filaretov@protonmail.com>

crates/nu-command/src/platform/reedline_commands/keybindings_list.rs

@@ -57,15 +57,14 @@ impl Command for KeybindingsList {
         call: &Call,
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
-        let records = if call.named.is_empty() {
+        let records = if call.named_len() == 0 {
             let all_options = vec!["modifiers", "keycodes", "edits", "modes", "events"];
             all_options
                 .iter()
                 .flat_map(|argument| get_records(argument, &call.head))
                 .collect()
         } else {
-            call.named
-                .iter()
+            call.named_iter()
                 .flat_map(|(argument, _)| get_records(argument.item.as_str(), &call.head))
                 .collect()
         };