Add string/binary type color to ByteStream (#12897)

# Description

This PR allows byte streams to optionally be colored as being
specifically binary or string data, which guarantees that they'll be
converted to `Binary` or `String` appropriately on `into_value()`,
making them compatible with `Type` guarantees. This makes them
significantly more broadly usable for command input and output.

There is still an `Unknown` type for byte streams coming from external
commands, which uses the same behavior as we previously did where it's a
string if it's UTF-8.

A small number of commands were updated to take advantage of this, just
to prove the point. I will be adding more after this merges.

# User-Facing Changes
- New types in `describe`: `string (stream)`, `binary (stream)`
- These commands now return a stream if their input was a stream:
  - `into binary`
  - `into string`
  - `bytes collect`
  - `str join`
  - `first` (binary)
  - `last` (binary)
  - `take` (binary)
  - `skip` (binary)
- Streams that are explicitly binary colored will print as a streaming
hexdump
  - example:
    ```nushell
    1.. | each { into binary } | bytes collect
    ```

# Tests + Formatting
I've added some tests to cover it at a basic level, and it doesn't break
anything existing, but I do think more would be nice. Some of those will
come when I modify more commands to stream.

# After Submitting
There are a few things I'm not quite satisfied with:

- **String trimming behavior.** We automatically trim newlines from
streams from external commands, but I don't think we should do this with
internal commands. If I call a command that happens to turn my string
into a stream, I don't want the newline to suddenly disappear. I changed
this to specifically do it only on `Child` and `File`, but I don't know
if this is quite right, and maybe we should bring back the old flag for
`trim_end_newline`
- **Known binary always resulting in a hexdump.** It would be nice to
have a `print --raw`, so that we can put binary data on stdout
explicitly if we want to. This PR doesn't change how external commands
work though - they still dump straight to stdout.

Otherwise, here's the normal checklist:

- [ ] release notes
- [ ] docs update for plugin protocol changes (added `type` field)

---------

Co-authored-by: Ian Manske <ian.manske@pm.me>

crates/nu-command/src/strings/str_/join.rs

@@ -1,4 +1,5 @@
 use nu_engine::command_prelude::*;
+use std::io::Write;
 
 #[derive(Clone)]
 pub struct StrJoin;
@@ -40,31 +41,40 @@ impl Command for StrJoin {
     ) -> Result<PipelineData, ShellError> {
         let separator: Option<String> = call.opt(engine_state, stack, 0)?;
 
-        let config = engine_state.get_config();
+        let config = engine_state.config.clone();
 
-        // let output = input.collect_string(&separator.unwrap_or_default(), &config)?;
-        // Hmm, not sure what we actually want.
-        // `to_formatted_string` formats dates as human readable which feels funny.
-        let mut strings: Vec<String> = vec![];
+        let span = call.head;
 
-        for value in input {
-            let str = match value {
-                Value::Error { error, .. } => {
-                    return Err(*error);
+        let metadata = input.metadata();
+        let mut iter = input.into_iter();
+        let mut first = true;
+
+        let output = ByteStream::from_fn(span, None, ByteStreamType::String, move |buffer| {
+            // Write each input to the buffer
+            if let Some(value) = iter.next() {
+                // Write the separator if this is not the first
+                if first {
+                    first = false;
+                } else if let Some(separator) = &separator {
+                    write!(buffer, "{}", separator)?;
                 }
-                Value::Date { val, .. } => format!("{val:?}"),
-                value => value.to_expanded_string("\n", config),
-            };
-            strings.push(str);
-        }
 
-        let output = if let Some(separator) = separator {
-            strings.join(&separator)
-        } else {
-            strings.join("")
-        };
+                match value {
+                    Value::Error { error, .. } => {
+                        return Err(*error);
+                    }
+                    // Hmm, not sure what we actually want.
+                    // `to_expanded_string` formats dates as human readable which feels funny.
+                    Value::Date { val, .. } => write!(buffer, "{val:?}")?,
+                    value => write!(buffer, "{}", value.to_expanded_string("\n", &config))?,
+                }
+                Ok(true)
+            } else {
+                Ok(false)
+            }
+        });
 
-        Ok(Value::string(output, call.head).into_pipeline_data())
+        Ok(PipelineData::ByteStream(output, metadata))
     }
 
     fn examples(&self) -> Vec<Example> {