Remove connection handling from swap execution

The swap should not be concerned with connection handling. This is
the responsibility of the overall application.

All but the execution-setup NetworkBehaviour are `request-response`
behaviours. These have built-in functionality to automatically emit
a dial attempt in case we are not connected at the time we want to
send a message. We remove all of the manual dialling code from the
swap in favor of this behaviour.

Additionally, we make sure to establish a connection as soon as the
EventLoop gets started. In case we ever loose the connection to Alice,
we try to re-establish it.

swap/tests/happy_path_restart_bob.rs

@@ -2,7 +2,7 @@ pub mod testutils;
 
 use swap::protocol::bob::BobState;
 use swap::protocol::{alice, bob};
-use testutils::bob_run_until::is_xmr_locked;
+use testutils::bob_run_until::{is_btc_locked, is_xmr_locked};
 use testutils::SlowCancelConfig;
 
 #[tokio::test]
@@ -32,3 +32,31 @@ async fn given_bob_restarts_after_xmr_is_locked_resume_swap() {
     })
     .await;
 }
+
+#[tokio::test]
+async fn given_bob_restarts_before_xmr_is_locked_resume_swap() {
+    testutils::setup_test(SlowCancelConfig, |mut ctx| async move {
+        let (bob_swap, bob_join_handle) = ctx.bob_swap().await;
+        let bob_swap = tokio::spawn(bob::run_until(bob_swap, is_btc_locked));
+
+        let alice_swap = ctx.alice_next_swap().await;
+        let alice_swap = tokio::spawn(alice::run(alice_swap));
+
+        let bob_state = bob_swap.await??;
+
+        assert!(matches!(bob_state, BobState::BtcLocked { .. }));
+
+        let (bob_swap, _) = ctx.stop_and_resume_bob_from_db(bob_join_handle).await;
+        assert!(matches!(bob_swap.state, BobState::BtcLocked { .. }));
+
+        let bob_state = bob::run(bob_swap).await?;
+
+        ctx.assert_bob_redeemed(bob_state).await;
+
+        let alice_state = alice_swap.await??;
+        ctx.assert_alice_redeemed(alice_state).await;
+
+        Ok(())
+    })
+    .await;
+}

swap/tests/testutils/mod.rs

@@ -9,7 +9,6 @@ use get_port::get_port;
 use libp2p::core::Multiaddr;
 use libp2p::{PeerId, Swarm};
 use monero_harness::{image, Monero};
-use std::convert::Infallible;
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 use std::time::Duration;
@@ -78,7 +77,7 @@ impl BobParams {
     }
 }
 
-pub struct BobEventLoopJoinHandle(JoinHandle<Result<Infallible>>);
+pub struct BobEventLoopJoinHandle(JoinHandle<()>);
 
 impl BobEventLoopJoinHandle {
     pub fn abort(&self) {