Implement worker advise commands

src/MxGateway.Worker/MxAccess/MxAccessStaSession.cs

@@ -94,6 +94,19 @@ public sealed class MxAccessStaSession : IDisposable
             cancellationToken);
     }
 
+    public Task<IReadOnlyList<RegisteredAdviceHandle>> GetRegisteredAdviceHandlesAsync(
+        CancellationToken cancellationToken = default)
+    {
+        if (session is null)
+        {
+            throw new InvalidOperationException("MXAccess COM session has not been started.");
+        }
+
+        return staRuntime.InvokeAsync(
+            () => session.HandleRegistry.AdviceHandles,
+            cancellationToken);
+    }
+
     public void Dispose()
     {
         if (disposed)