p2p: Store `IncomingSignalingMethod::P2p` `dial_opts`

[iostat]

p2p_connection_incoming_reducer.rs:57

When an incoming connection arrives via P2P relay, dial_opts is set to None. This means the node cannot reconnect to the peer later if the connection drops. No fallback mechanism exists for relay-initiated connections. In the case of transient network failures, the remote end might still be listening and would not need a new signaling handshake to reinitiate a connection...

IncomingSignalingMethod::P2p { .. } => return None,