Don't depend on Buffer to be compatible with Webpack 5 by default

[davidyuk]

I have problems using this package in a project created by create-react-app@5.

Reproduction: https://github.com/davidyuk/reproductions/tree/cra-5-blakejs

The error I have (in browser console):

Uncaught ReferenceError: Buffer is not defined
at Object.normalizeInput (util.js:10:1)
at blake2b (blake2b.js:441:1)

It happens because Webpack 5 dropped automatic polyfilling of Nodejs modules: https://webpack.js.org/blog/2020-10-10-webpack-5-release/#automatic-nodejs-polyfills-removed. It can be fixed in webpack configuration, but it can't be changed without ejecting the react project (that some users may not want to do for simplicity).

Since node@4, Buffer inherits Uint8Array, so a separate input instanceof Buffer check is extra and I'm proposing to remove it.

Regarding the second reference to Buffer: let's use TextEncoder class, it is widely supported now (except for IE 11). If necessary it can be polyfilled on a side of the project that uses this library.

As an alternative to the proposed fix, blakejs can explicitly depend on buffer package.

[nazar-pc]

On Node.js Buffer extended Uint8Array since forever ago, so input instanceof Buffer was no-op in practice anyway.

[nazar-pc]

We'll need @dcposch to publish new release though

[marc0olo]

@nazar-pc @dcposch can we get this merged and have a new release? that would be awesome. it's quite urgent. otherwise we need to release and publish our fork on npm.

please let us know until monday

[nazar-pc]

I can merge it, but I don't have permissions to publish it to NPM.

[dcposch]

Pushing to npm.

Chang e looks great to me, thanks @nazar-pc @davidyuk