IOSuccess / IOFailure and match-case

I don't really see the point of `IOSuccess` and `IOFailure`. From one hand, `IOResult.from_value(1) == IOSuccess.from_value(1)`. Actually ,`IOSuccess.from_value(1) == IOFailure.from_value(1)`.
I would also expect some benefit when using it in a match-case. Something like:

```python
value = IOSuccess.from_value(1)
match value:
case IOSuccess(v): assert(v == 1)
case _: pass
```

However, the "correct" code is

```python
value = IOSuccess.from_value(1)
match value:
case IOResult(Success(v)): assert(v == 1)
case _: pass
```

Therefore, `IOSuccess` and `IOFailure` as aliases are quite confusing. Don't you think?

先找出 IOSuccess、IOFailure、IOResult 和 Success 的定義，接著重現 issue 中的兩個 match-case 範例與相等比較。預期行為以及是否應變更這些別名在此處尚未決定，因此要完成這項工作，需要一個已達成共識的設計及相應的測試。

由索引模型根據 Issue 內容生成。