message: track caller to give better line numbers on test errors
diff: @@ -24,6 +24,7 @@ pub(crate) struct TestContextImpl {
  }
  impl TestContextImpl {
  + #[track_caller]
  pub(crate) fn assert_log(&self, expected_log: &[&str]) {
  let expected_text = &format!("{:#?}", expected_log);
  let actual_text = &format!("{:#?}", self.log().take());
  