Defensive handling of errors when transposing (#14096)

# Description
This PR aims to close #14027, in which it was noticed that the transpose
command "swallows" error messages.

*Note that in exploring the linked issue, [other situations were
identified](https://github.com/nushell/nushell/issues/14027#issuecomment-2414602880)
which also produce inconsistent behaviour. These have knowingly been
omitted from this PR, to minimize its scope, and since they seem to have
a different cause. It's probably best to make a separate issue/PR in
which to tackle a broader scan of error handling, with a suspected
relation to streams.*

# User-Facing Changes
The user will see errors from deeper in the pipeline, in case the errors
originated there.

# Tests + Formatting
Toolkit PR check was run successfully.

One test was added, covering this exact situation, in order to prevent
regressions.
The bug is relatively obscure, so it may be prone to reappear during
refactorings.

crates/nu-command/src/filters/transpose.rs

@@ -175,6 +175,12 @@ pub fn transpose(
 
     let metadata = input.metadata();
     let input: Vec<_> = input.into_iter().collect();
+    // Ensure error values are propagated
+    for i in input.iter() {
+        if let Value::Error { .. } = i {
+            return Ok(i.clone().into_pipeline_data_with_metadata(metadata));
+        }
+    }
 
     let descs = get_columns(&input);
 

crates/nu-command/tests/commands/transpose.rs

@@ -20,3 +20,15 @@ fn row_but_all() {
 
     assert!(actual.out.contains("foo: [1, 2]"));
 }
+
+#[test]
+fn throw_inner_error() {
+    let error_msg = "This message should show up";
+    let error = format!("(error make {{ msg: \"{}\" }})", error_msg);
+    let actual = nu!(format!(
+        "[[key value]; [foo 1] [foo 2] [{} 3]] | transpose",
+        error
+    ));
+
+    assert!(actual.err.contains(error.as_str()));
+}