A set of fixes for stderr redirect (#7219)

# Description

This is a set of fixes to `err>` to make it work a bit more predictably.

I've also revised the tests, which accidentally tested the wrong thing
for redirection, but should be more correct now.

# User-Facing Changes

_(List of all changes that impact the user experience here. This helps
us keep track of breaking changes.)_

# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.

crates/nu-cli/src/eval_file.rs

@@ -74,6 +74,14 @@ pub fn print_table_or_error(
     // Change the engine_state config to use the passed in configuration
     engine_state.set_config(config);
 
+    if let PipelineData::Value(Value::Error { error }, ..) = &pipeline_data {
+        let working_set = StateWorkingSet::new(engine_state);
+
+        report_error(&working_set, error);
+
+        std::process::exit(1);
+    }
+
     match engine_state.find_decl("table".as_bytes(), &[]) {
         Some(decl_id) => {
             let command = engine_state.get_decl(decl_id);

crates/nu-cli/src/repl.rs

@@ -528,7 +528,7 @@ pub fn evaluate_repl(
             Err(err) => {
                 let message = err.to_string();
                 if !message.contains("duration") {
-                    println!("Error: {:?}", err);
+                    eprintln!("Error: {:?}", err);
                     // TODO: Identify possible error cases where a hard failure is preferable
                     // Ignoring and reporting could hide bigger problems
                     // e.g. https://github.com/nushell/nushell/issues/6452