Bubble up errors passed to complete (#11313)

Errors passed in `PipelineData::Value` get thrown in `complete` now.

Also added two simple tests for the command.

Fix #11187
Fix #10204

crates/nu-command/src/system/complete.rs

@@ -101,6 +101,8 @@ impl Command for Complete {
 
                 Ok(Value::record(record, call.head).into_pipeline_data())
             }
+            // bubble up errors from the previous command
+            PipelineData::Value(Value::Error { error, .. }, _) => Err(*error),
             _ => Err(ShellError::GenericError {
                 error: "Complete only works with external streams".into(),
                 msg: "complete only works on external streams".into(),