fix(node): Remove keep_alive::Behaviour

[oblique]

This was preventing ping::Behaviour to close a broken connections.

[fl0rek]

🚀

[zvolin]

Now I'm wondering what to do with the peer tracker. If nodes will be disconnecting in idle, we shouldn't treat the Identified state as an upgrade of connected but rather the separate thing, like trusted? Also Identified shouldn't affect is_connected, am I correct?

[oblique]

Identified means we received what protocols the node supports after the connection. If it gets disconnected the identification get invalidated because we don't know if process was stopped manually to be started in a different version. Versions can support different protocols.

On the other hand, we don't make any use of this information and I think we will never. So we can remove the Identified state.

[zvolin]

Doesn't identify also provide us listening addresses we put into PeerInfo?

[oblique]

True. But we can use add_addresses for that.