[Feature] Add DNS resolver for node connections

[raychu86]

🚀 Feature

A DNS resolver can be added to snarkOS to facilitate node connections.

Motivation

Node connections are purely reliant on IP addresses, which is much more difficult to reason about than a human readable URL. A simple DNS resolver will greatly aid in manual connection to nodes and delineation between bootnodes.

Implementation

A DNS resolver such as ns-dns-tokio could be used to translate URLs into IPs that the node can connect to.

[damons]

Are we using URLs? Would a simple hostname not do instead of just the IP? This way one could rely on the OS to do the resolution? Curious why we need a whole library to resolve names when that's usually a system-level thing.

[damons]

Unless we mean reverse lookups, which would negatively impact performance dramatically, I'd think.