MapGrpcService non static alternative

Hello,
I am migrating server from Grpc.Core to Grpc.AspNetCore.Server.
In Grpc.Core I was using:
```
Grpc.Core.Server server = new Grpc.Core.Server()
{
Services = { _instanceOfMyServiceImplementation.GetServiceDefinition() },
Ports =
{
new ServerPort("0.0.0.0", 5555, Grpc.Core.ServerCredentials.Insecure)
}
};

```
In my service was following registration method and handler as:
```
public ServerServiceDefinition GetServiceDefinition()
{
return ServerServiceDefinition.CreateBuilder()
.AddMethod(_duplexCommunicationMethod, DuplexCommunication).Build();
}
```
for binding incommning calls to specific nonstatic processing method and handler.

I am now migrating to Grpc.AspNetCore.Server. I would like to avoid static classes, methods if possible. I was able to create my service as singleton. But I am not able to register processing _duplexCommunicationMethod method and handler from my instanced service implementation. I would need endpoints.MapGrpcService alternative mapping from specific instance not from Type and using static methods. Something like this:
```
var instanceOfMyServiceImplementation =
var builder = Host.CreateDefaultBuilder().ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseKestrel();
webBuilder.ConfigureServices(services =>
{
services.AddSingleton(communicationService);
services.AddGrpc();
});

webBuilder.Configure((context, app) =>
{
app.UseRouting();
app.UseEndpoints(endpoints =>
{
endpoints.BindGrpcService(instanceOfMyServiceImplementation.BindService());
});
});
});

```
with BindService like this:
```
public ServiceBinderBase BindService ()
{
ServiceBinderBase sbb = new ServiceBinderBase();
sbb.AddMethod(_duplexCommunicationMethod, DuplexCommunication);
return sbb;
}
```
Is it possible? Thanks

Start with the ASP.NET Core gRPC endpoint entry point, endpoints.MapGrpcService, and compare it with the Grpc.Core GetServiceDefinition and BindService examples shown in the issue. Determine whether instance-based binding from an external DI container is supported; done means documenting a supported registration path or clearly recording that this mapping is unavailable.

Written by the indexing model from the issue text.