Create a gRPC client and server in ASP.NET Core 3.0 using Visual Studio

3.1 update for gRPC-start tutorial and its two sample apps (#18103)

* 3.1 udpate for Updated gRPC-start tutorial and its two sample apps

* Update GrpcGreeter.csproj

Update per review feedback.

* Update GrpcGreeter.csproj

Reversing change that caused the merge issue.

* Update grpc-start.md

Resolving merge conflict with mass no-loc for razor fix that occurred today.

* Update GrpcGreeter.csproj

Fixing per review.

* Update grpc-start.md

Addressing merge conflict - ms.date line