implement conversion to new protobuf-based entity-related orchestration history events, as used by DTS, and enable entities by default when using DTS backend.

Author: sebastianburckhardt

eng/proto

@@ -87,7 +87,10 @@ static void ConfigureSchedulerOptions(
 
         builder.Services.TryAddEnumerable(
             ServiceDescriptor.Singleton<IConfigureOptions<GrpcDurableTaskClientOptions>, ConfigureGrpcChannel>());
-        builder.UseGrpc(_ => { });
+        builder.UseGrpc((GrpcDurableTaskClientOptions options) =>
+        {
+            options.EnableEntitySupport = true;
+        });
     }
 
     /// <summary>