pub async fn grade(
submissions: Vec<(Box<[SolutionData]>, Vec<Option<ProblemResponse>>)>,
) -> Result<Vec<Vec<ProblemFeedbackJson>>, ServerFnError<String>>pub async fn grade(
submissions: Vec<(Box<[SolutionData]>, Vec<Option<ProblemResponse>>)>,
) -> Result<Vec<Vec<ProblemFeedbackJson>>, ServerFnError<String>>