Async'ify our test suite

.. as LDK Node is moving towards a more `async` core, it starts to make
sense to switch our test suite over to be `async`.

This change should make our CI more efficient (as not every node will
spawn its independent runtime, but we just have one runtime per test
created) and also makes sure we won't run into any edge cases arising
from blocking test threads that are executing other async tasks.

Author: tnull

src/event.rs

@@ -1625,7 +1625,6 @@ mod tests {
 
 		// Check we get the expected event and that it is returned until we mark it handled.
 		for _ in 0..5 {
-			assert_eq!(event_queue.wait_next_event(), expected_event);
 			assert_eq!(event_queue.next_event_async().await, expected_event);
 			assert_eq!(event_queue.next_event(), Some(expected_event.clone()));
 		}
@@ -1640,7 +1639,7 @@ mod tests {
 		.unwrap();
 		let deser_event_queue =
 			EventQueue::read(&mut &persisted_bytes[..], (Arc::clone(&store), logger)).unwrap();
-		assert_eq!(deser_event_queue.wait_next_event(), expected_event);
+		assert_eq!(deser_event_queue.next_event_async().await, expected_event);
 
 		event_queue.event_handled().unwrap();
 		assert_eq!(event_queue.next_event(), None);
@@ -1709,32 +1708,5 @@ mod tests {
 			}
 		}
 		assert_eq!(event_queue.next_event(), None);
-
-		// Check we operate correctly, even when mixing and matching blocking and async API calls.
-		let (tx, mut rx) = tokio::sync::watch::channel(());
-		let thread_queue = Arc::clone(&event_queue);
-		let thread_event = expected_event.clone();
-		std::thread::spawn(move || {
-			let e = thread_queue.wait_next_event();
-			assert_eq!(e, thread_event);
-			thread_queue.event_handled().unwrap();
-			tx.send(()).unwrap();
-		});
-
-		let thread_queue = Arc::clone(&event_queue);
-		let thread_event = expected_event.clone();
-		std::thread::spawn(move || {
-			// Sleep a bit before we enqueue the events everybody is waiting for.
-			std::thread::sleep(Duration::from_millis(20));
-			thread_queue.add_event(thread_event.clone()).unwrap();
-			thread_queue.add_event(thread_event.clone()).unwrap();
-		});
-
-		let e = event_queue.next_event_async().await;
-		assert_eq!(e, expected_event.clone());
-		event_queue.event_handled().unwrap();
-
-		rx.changed().await.unwrap();
-		assert_eq!(event_queue.next_event(), None);
 	}
 }