Convert to named export and add native esm support

[TrySound]

References
#37
https://github.com/rollup/rollup/blob/master/build-plugins/emit-module-package-file.js
https://unpkg.com/nanoevents@5.1.5/package.json

Node supports unflagged esm since v13. In this diff I changed default
import to memoizeOne named one.

import { memoizeOne } from 'memoize-one';
const { memoizeOne } = require('memoize-one');
const { memoizeOne } = window.memoizeOne;

The main reason is TS support without fighting with default commonjs/esm
interop which forces to import a function as a namespace.

import * as memoizeOne from 'memoize-one';

This is incorrect. Module namespace is an object due spec.

Libraries like nanoevents and nanoid ended with named export aswell.
See details here ai/nanoid#128

Also I simplified generated bundles to one umd and one esm because project does not have dependencies and process.env.NODE_ENV usages.

[theKashey]

A breaking change :(

[TrySound]

Or inconsistent usage

[alexreardon]

I am not sure what to do with this one. Open to advice!

[TrySound]

Major release won't break anybody. See here's big migration guide
https://github.com/ai/nanoid/releases/tag/3.0.0

[theKashey]

Well, @alexreardon, what about bumping major version and realising a simple codeshift(or what we are using nowadays) to make migration a joy?

[alexreardon]

Is this still needed @TrySound ?

[TrySound]

Maybe node es modules support but it will require major bump.

[alexreardon]

Named import is now supported

// default export
export default memoizeOne;
// named export
export { memoizeOne };

Any esm support stuff still needed?

(i'll reopen if so)