Adds MapGrpcService overload for ServerServiceDefinition

[aka-nse]

This is a duplicate of #2535.
I made a serious operational error while tracking master, so I created a new pull request.
I apologize for the inconvenience.

---

Is your feature request related to a problem? Please describe.

This PR is implement for #2236.

ServerServiceDefinition is defined in Grpc.Core.Api library, and it was a prefer way to implement gRPC server with Grpc.Core.
In current grpc-dotnet, the server should be implemented on Asp.Net web application DI container via GrpcEndpointRouteBuilderExtensions.MapGrpcService generic method.
The APIs in this proposal bridges legacy way into grpc-dotnet to enable to migrate easier.

Describe the solution you'd like

2 overloads of GrpcEndpointRouteBuilderExtensions.MapGrpcService are added:

public static class GrpcEndpointRouteBuilderExtensions
{
    public static GrpcServiceEndpointConventionBuilder MapGrpcService(
        this IEndpointRouteBuilder builder,
        ServerServiceDefinition serviceDefinition);

    public static GrpcServiceEndpointConventionBuilder MapGrpcService(
        this IEndpointRouteBuilder builder,
        Func<IServiceProvider, ServerServiceDefinition> getServiceDefinition);
}

This change enables to map gRPC services via Grpc.Core.ServerServiceDefinition, therefore migration from Grpc.Core can be more easier.

Changes in this PR

• Grpc.Core.Api

  • makes Grpc.Core.ServerServiceDefinition.BindService(ServiceBinderBase) method as public*

• Grpc.AspNetCore.Server

  • adds new extension methods in Microsoft.AspNetCore.Builder.GrpcEndpointRouteBuilderExtensions class
    • MapGrpcService(this IEndpointRouteBuilder, ServerServiceDefinition)*
    • MapGrpcService(this IEndpointRouteBuilder, Func<IServiceProvider, ServerServiceDefinition>)*
  • appends service entries of ServerCallHandlerFactory and ServiceRouteBuilder (non-generic) on Microsoft.Extensions.DependencyInjection.AddServiceOptions method**
  • adds new class Grpc.AspNetCore.Server.Internal.EndpointServiceBinder to bind methods in ServerServiceDefinition into ASP.Net core web application server*
  • adds following internal classes that bind service via delegate instances instead of type argument:
    • Grpc.AspNetCore.Server.Internal.ServerCallHandlerFactory class*
    • Grpc.AspNetCore.Server.Model.Internal.ServiceRouteBuilder class*
    • ServerCallHandlerBase*, UnaryServerCallhandler*, ServerStreamingServerCallHandler*, ClientStreamingServerCallHandler*, and DuplexStreamingServerCallHandler* classes in Grpc.AspNetCore.Server.Internal.CallHandlers namespace
    • ServerMethodInvokerBase*, UnaryServerMethodInvoker*, ServerStreamingServerMethodInvoker*, ClientStreamingServerMethodInvoker*, and DuplexStreamingServerMethodInvoker* classes in Grpc.Shared.Server namespace
  • extracts shared interface between ServerCallHandlerFactory and ServerCallHandlerFactory<TService> into IServerCallHandlerFactory*

• test

  • adds test cases for new overloads of MapGrpcService

• examples

  • modifies examples/README.md
  • adds new example project examples/GreeterByServiceDefinition
  • appends implementation of Grpc.AspNetCore.Server.Tests.TestObjects.Services.WithAttribute.GreeterWithAttribute.BindService method

Describe alternatives you've considered

This commit contains concrete code as far as I can write, but I do not care about these implementations.
I welcome better ways to realize this suggestion.

Additional context

No response

[VAllens]

This is great and exactly what I needed.
Very useful for scenarios where a custom service definition is needed.
Now, any progress on this?
How should we move forward with this PR?

Currently, I copy the service code generated by Grpc.Tools and rewrite them.
Then having the specific service implementation class derive from me.
Follow the BindServiceMethod convention and let it be auto-bound.

[floozie]

Is this ever going to be implemented?

[aka-nse]

@floozie
Although I'm monitoring this issue and keeping it in sync with the master branch, the lack of response from the owners is all I can do.
If I have made a mistake in the contribution process, I would be happy to be pointed it out.

[JamesNK]

Hi

I refactored your PR to reduce duplication. See changes here: #2634. Are you ok with using those changes?