Automatic Index Publishing

[dszlachta]

We need to automate index publishing at some point. It can be also used for publishing names database.
This means performing a send operation on chain, so we'd need to add this feature to chifra state.
When it comes to managing keys, go-ethereum already has a mechanism for that and I believe we should reuse it: https://pkg.go.dev/github.com/ethereum/[email protected]/accounts/keystore

Apart from the implementation, we can leverage Safe to have an account with a daily spending limit.