New: basic compare functions lt, lte, gt, gte

[Harris-Miller]

This MR improves the typings for lt, lte, gt, and gte to include all Ord types

export type Ord = number | string | boolean | Date;

It also corrects the curry typing and removes the incorrect operand switching

// this is not correct!
export function gt(__: Placeholder): (b: number, a: number) => boolean;

Please note the addition and use of WidenLiterals. This is important only when you have

// when
export function gt<T extends Ord>(a: T): (b: T) => boolean;
gt(2)(1); // error: `T` is type literal `2`, and `1 !== 2`

// fix with `WidenLiterals`
export function gt<T extends Ord>(a: T): (b: WidenLiterals<T>) => boolean;
gt(2)(1); // ok! `T` is now `number`, and not `2`

The overloads orders are also updated so it's least to most arity. This is important because of how typescript used the last defined overload when accepting a function as an argument. When you do flip(lt) for example, in the previous order flip would have received the type (a: Ord) => (b: ord) = boolean. That is incorrect. The new ordering makes it so it receives (a: Ord, b: Ord) => boolean

To support that change an additional overload to the return type of flip had to be added for currying.