[function] Add flip function

[Ailrun]

Description

For many cases, including #38, changing argument order is extremely useful, and this function is not so hard to implement if we consider only basic cases.

type FlipResult<F extends (a: never) => (b: never) => any> = F extends (a: infer A) => infer BR ? (
  BR extends (b: infer B) => infer R ?
    Fun<[B], Fun<[A], R>> :
    never
  ) :
  never;
function flip<F extends Fun<[never], Fun<[never], any>>(f: F):  FlipResult<F> {
  return function (b) {
    return function (a) {
      return f(a)(b);
    };
  };
}