Function headless_lms_models::peer_or_self_review_submissions::get_users_submission_count_for_exercise_and_course_instance

pub async fn get_users_submission_count_for_exercise_and_course_instance(
    conn: &mut PgConnection,
    user_id: Uuid,
    exercise_id: Uuid,
    course_instance_id: Uuid
) -> ModelResult<u32>