Refactor EventEmitter to separate package

[AuHau]

The confirmation and blockchain event handling can be beneficial for more people, so we should release it as separate package.

I will need it for the Pinning Service anyway.

[AuHau]

Future repo: https://github.com/rsksmart/web3-events

[julianmrodri]

@AuHau maybe we can close this issue now that web3-events is implemented?

[AuHau]

👍