Created network, storage and protocol modules. Organised
files into the modules where the belong.
xmr_btc crate moved into isolated modulein swap crate.
Remove the xmr_btc module and integrate into swap crate.
Consolidate message related code
Reorganise imports
Remove unused parent Message enum
Remove unused parent State enum
Remove unused dependencies from Cargo.toml
As Bob is dialing Alice, we now ensure that we are connected to Alice
at each step that needs communication.
If we are not connected, we proceed with dialing.
In an attempt to improve libp2p usage, we also add known address of
Alice first and only use peer_id to dial.
This ensures that we use the expected peer id.
