Change the error style during tests to plain (#13061)

# Description

This fixes issues with trying to run the tests with a terminal that is
small enough to cause errors to wrap around, or in cases where the test
environment might produce strings that are reasonably expected to wrap
around anyway. "Fancy" errors are too fancy for tests to work
predictably 😉

cc @abusch

# User-Facing Changes

- Added `--error-style` option for use with `--commands` (like
`--table-mode`)

# Tests + Formatting

Surprisingly, all of the tests pass, including in small windows! I only
had to make one change to a test for `error make` which was looking for
the box drawing characters miette uses to determine whether the span
label was showing up - but the plain error style output is even better
and easier to match on, so this test is actually more specific now.

crates/nu-cli/src/eval_cmds.rs

@@ -8,15 +8,45 @@ use nu_protocol::{
 };
 use std::sync::Arc;
 
+#[derive(Default)]
+pub struct EvaluateCommandsOpts {
+    pub table_mode: Option<Value>,
+    pub error_style: Option<Value>,
+    pub no_newline: bool,
+}
+
 /// Run a command (or commands) given to us by the user
 pub fn evaluate_commands(
     commands: &Spanned<String>,
     engine_state: &mut EngineState,
     stack: &mut Stack,
     input: PipelineData,
-    table_mode: Option<Value>,
-    no_newline: bool,
+    opts: EvaluateCommandsOpts,
 ) -> Result<(), ShellError> {
+    let EvaluateCommandsOpts {
+        table_mode,
+        error_style,
+        no_newline,
+    } = opts;
+
+    // Handle the configured error style early
+    if let Some(e_style) = error_style {
+        match e_style.coerce_str()?.parse() {
+            Ok(e_style) => {
+                Arc::make_mut(&mut engine_state.config).error_style = e_style;
+            }
+            Err(err) => {
+                return Err(ShellError::GenericError {
+                    error: "Invalid value for `--error-style`".into(),
+                    msg: err.into(),
+                    span: Some(e_style.span()),
+                    help: None,
+                    inner: vec![],
+                });
+            }
+        }
+    }
+
     // Translate environment variables from Strings to Values
     convert_env_values(engine_state, stack)?;