[Enhancement] Consider moving networking utilities to their own crate

[Davidson-Souza]

Describe the enhancement

In floresta-wire we have a couple a utilities, such as Proxy and DNS helpers. In the future we will bring BitcoinSocketAddr (#984) and helpers for Onion and I2P addresses. They feel a bit off-topic for wire, and would probably be better off somewhere else.

Source: #984 (comment)

[luisschwab]

I got this one