[RFC] tsconfig 是否应该开启 strict 或 strictNullChecks

WHY：不开启strictNullChecks的话会忽略所有的 null 和 undefined

举个例子：

useMergedState 中接受了泛型T作为内部的 innerValue 类型，但根据 L60 开始的代码

  // Sync value back to `undefined` when it from control to un-control
  useLayoutUpdateEffect(() => {
    if (!hasValue(value)) {
      setInnerValue(value);
    }
  }, [value]);

实际上 innerValue 的类型是T | undefined，因为没有开启 strictNullChecks 导致没有警告

该函数使用中，需要显性去指定泛型为 T | undefined 才能获取到实际正确的类型，如：

const [v] = useMergedState<string[]>(...) => const [v] = useMergedState<string[] | undefined>(...)

前者的写法，v的类型会忽略 undefined类型，导致后续编码产生错误

以上为我在debug该issue时发现： https://github.com/ant-design/pro-components/issues/6652

个人见解，欢迎讨论😁

Start by reviewing the repository's tsconfig and the useMergedState.ts example, especially the generic declaration near line 19 and the effect beginning around line 60. Consider the linked pro-components issue for context, then determine whether enabling strict or strictNullChecks is appropriate and define the resulting type-safety acceptance criteria.