163. 解包

如何构建一个工具类型，能够“解包”数组、函数、Promise 和元组？

例如：

type Res1 = Unbox<string> // expected to be string
type Res2 = Unbox<() => number> // expected to be number
type Res3 = Unbox<boolean[]> // expected to be boolean
type Res4 = Unbox<Promise<boolean>> // expected to be boolean

附加题1：我们能让它递归吗？

type Res = Unbox<() => () => () => () => number> // expected to be number

附加题2：我们能控制递归的深度吗？

type Res = Unbox<() => () => () => () => number, 3> // expected to be () => number