Refactor project structure and add initial files

aspire-sample/aspire-sample.AppHost/Program.cs

@@ -0,0 +1,9 @@
+var builder = DistributedApplication.CreateBuilder(args);
+
+var apiService = builder.AddProject<Projects.aspire_sample_ApiService>("apiservice");
+
+builder.AddProject<Projects.aspire_sample_Web>("webfrontend")
+    .WithExternalHttpEndpoints()
+    .WithReference(apiService);
+
+builder.Build().Run();