[API] Provide a default property implementation for IErrorWorker.

src/Marille/Hub.cs

@@ -120,7 +120,8 @@ async Task ConsumeChannel<T> (string name, TopicConfiguration configuration, Cha
 					// the error task in a try/catch to make sure that if the user did raise an exception, we do not
 					// crash the whole consuming task. Sometimes java was right when adding exceptions to a method signature
 					try {
-						if (errorWorker.UseBackgroundThread)
+						var _ = errorWorker.TryGetUseBackgroundThread (out var useBackgroundThread);
+						if (useBackgroundThread)
 							await Task.Run (async () => {
 								await errorWorker.ConsumeAsync (
 									item.Payload, item.Exception, cancellationToken).ConfigureAwait (false);

src/Marille/IErrorWorker.cs

@@ -11,7 +11,7 @@ public interface IErrorWorker<in T> : IDisposable, IAsyncDisposable where T : st
 	/// Specifies if the worker should use a background thread to process the messages. If set to
 	/// true the implementation of the worker should be thread safe.
 	/// </summary>
-	public bool UseBackgroundThread { get; }
+	public bool UseBackgroundThread { get => false; } 
 
 	/// <summary>
 	///

src/Marille/WorkerExtensions.cs

@@ -14,4 +14,15 @@ public static bool TryGetUseBackgroundThread<T> (this IWorker<T> worker, out boo
 			return false;
 		}
 	}
+
+	public static bool TryGetUseBackgroundThread<T> (this IErrorWorker<T> worker, out bool useBackgroundThread) where T : struct
+	{
+		useBackgroundThread = false;
+		try {
+			useBackgroundThread = worker.UseBackgroundThread;
+			return true;
+		} catch {
+			return false;
+		}
+	}
 }