Use eosio.wrap instead of eosio.sudo with --sudo-wrap

[abourget]

We won't change the name of --sudo-wrap because it's very explicit and to the point.

This implies a change in eos-go under eos-go:sudo, which I guess we'll also rename to wrap.

We could have a --wrap-account with default value there, in case another network uses something different from eosio.wrap ? Let's start simple, with a fixed value.