Function headless_lms_models::user_exercise_states::get_or_create_user_exercise_state

pub async fn get_or_create_user_exercise_state(
    conn: &mut PgConnection,
    user_id: Uuid,
    exercise_id: Uuid,
    course_instance_id: Option<Uuid>,
    exam_id: Option<Uuid>
) -> ModelResult<UserExerciseState>