implement message subscribing and worker

dotnet/AipsWorker/Program.cs

@@ -0,0 +1,21 @@
+using AipsCore.Infrastructure.DI;
+using AipsWorker;
+using AipsWorker.Utilities;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+
+LoadingDotEnv.TryLoad();
+
+var builder = Host.CreateDefaultBuilder(args);
+
+builder.ConfigureServices((context, services) =>
+{
+    services.AddAips(context.Configuration);
+    services.AddAipsMessageHandlers();
+
+    services.AddHostedService<WorkerService>();
+});
+
+var app = builder.Build();
+    
+await app.RunAsync();