feat: switch to esm

[achingbrain]

Refactors the code to be ESM. Dual publishes CJS and ESM for maximum compatibility.

There are no default exports, so code similar to:

import IPFS from 'ipfs'

const ipfs = await IPFS.create()

should be refactored to:

import { create } as IPFS from 'ipfs'

const ipfs = await create()

BREAKING CHANGE: There are no default exports and everything is now dual published as ESM/CJS