Node address format

[tzdybal]

Optimint internally use libp2p for networking. This means addresses are represented as Multiaddr.
Cosmos-SDK use following format: <NODE_ID>@<IP>:<PORT>.

Currently, addresses from cosmos-sdk format are translated to multiaddresses. This ensures smooth reuse of tendermint/cosmos-sdk configuration, and should look more familiar to users/developers.

On the other hand, using multiaddr "everywhere" (in configs, logs, params, etc) will simplify the code.

[tzdybal]

Manual translation of addresses is less flexible (to use for example "ip6" or any other supported format we need to change the code).

[tzdybal]

ref: #14 (comment)