Better Web Support

[AlbertoElias]

This library depends on https://github.com/indutny/asn1.js which only works on Node, depending on the Buffer API. For example: https://github.com/indutny/asn1.js/blob/master/lib/asn1/base/buffer.js#L9 So we can't use UInt8Arrays instead from our code when interacting with js-libp2p-crypto, we necessarily need to use a Buffer polyfill.