ListStream touchup (#12524)

# Description

Does some misc changes to `ListStream`:
- Moves it into its own module/file separate from `RawStream`.
- `ListStream`s now have an associated `Span`.
- This required changes to `ListStreamInfo` in `nu-plugin`. Note sure if
this is a breaking change for the plugin protocol.
- Hides the internals of `ListStream` but also adds a few more methods.
- This includes two functions to more easily alter a stream (these take
a `ListStream` and return a `ListStream` instead of having to go through
the whole `into_pipeline_data(..)` route).
  -  `map`: takes a `FnMut(Value) -> Value`
  - `modify`: takes a function to modify the inner stream.

crates/nu-command/src/formats/from/json.rs

@@ -84,8 +84,11 @@ impl Command for FromJson {
                     .collect()
             };
 
-            Ok(converted_lines
-                .into_pipeline_data_with_metadata(metadata, engine_state.ctrlc.clone()))
+            Ok(converted_lines.into_pipeline_data_with_metadata(
+                span,
+                engine_state.ctrlc.clone(),
+                metadata,
+            ))
         } else if strict {
             Ok(convert_string_to_value_strict(&string_input, span)?
                 .into_pipeline_data_with_metadata(metadata))

crates/nu-command/src/formats/from/msgpack.rs

@@ -109,10 +109,9 @@ MessagePack: https://msgpack.org/
         call: &Call,
         input: PipelineData,
     ) -> Result<PipelineData, ShellError> {
-        let span = input.span().unwrap_or(call.head);
         let objects = call.has_flag(engine_state, stack, "objects")?;
         let opts = Opts {
-            span,
+            span: call.head,
             objects,
             ctrlc: engine_state.ctrlc.clone(),
         };
@@ -126,10 +125,10 @@ MessagePack: https://msgpack.org/
                 stdout: Some(raw_stream),
                 ..
             } => read_msgpack(ReadRawStream::new(raw_stream), opts),
-            _ => Err(ShellError::PipelineMismatch {
+            input => Err(ShellError::PipelineMismatch {
                 exp_input_type: "binary".into(),
                 dst_span: call.head,
-                src_span: span,
+                src_span: input.span().unwrap_or(call.head),
             }),
         }
     }
@@ -257,7 +256,7 @@ pub(crate) fn read_msgpack(
                 None
             }
         })
-        .into_pipeline_data(ctrlc))
+        .into_pipeline_data(span, ctrlc))
     } else {
         // Read a single value and then make sure it's EOF
         let result = read_value(&mut input, span, 0)?;

crates/nu-command/src/formats/to/text.rs

@@ -1,6 +1,6 @@
 use chrono_humanize::HumanTime;
 use nu_engine::command_prelude::*;
-use nu_protocol::{format_duration, format_filesize_from_conf, Config, ListStream, RawStream};
+use nu_protocol::{format_duration, format_filesize_from_conf, Config, RawStream, ValueIterator};
 
 #[derive(Clone)]
 pub struct ToText;
@@ -41,7 +41,7 @@ impl Command for ToText {
             Ok(PipelineData::ExternalStream {
                 stdout: Some(RawStream::new(
                     Box::new(ListStreamIterator {
-                        stream,
+                        stream: stream.into_inner(),
                         separator: line_ending.into(),
                         config: config.clone(),
                     }),
@@ -86,7 +86,7 @@ impl Command for ToText {
 }
 
 struct ListStreamIterator {
-    stream: ListStream,
+    stream: ValueIterator,
     separator: String,
     config: Config,
 }