Function get_exercise_slide_submission_info 

pub async fn get_exercise_slide_submission_info(
    conn: &mut PgConnection,
    exercise_slide_submission_id: Uuid,
    user_id: Uuid,
    fetch_service_info: impl Fn(Url) -> BoxFuture<'static, ModelResult<ExerciseServiceInfoApi>>,
    include_deleted_tasks: bool,
    file_store: &dyn FileStore,
    app_conf: &ApplicationConfiguration,
) -> ModelResult<ExerciseSlideSubmissionInfo>