gRPC C#: changes to gRPC nugets in the upcoming v1.19.0 release

[Jan Tattermusch]

Hi gRPC C# users,

in the upcoming release, we are making two improvements to the nuget packages:

1. The nuget packages are now signed (see nuget package signing for details) and all the DLL files contained in them are also Authenticode signed. This allows for better integrity verification of the nugets and requires no changes on your side.

2. In order to be able to support alternative gRPC C# implementations while maintaining API compatibility, we decided to split the Grpc.Core nuget package into Grpc.Core.Api (which contains the public APIs and can be used by other .NET implementations) and Grpc.Core (which has the actual implementation). The changes made are fully source & binary compatible, but we encourage users to test the new prerelease packages anyway to make sure everything works as expected. Details of the change: https://github.com/grpc/grpc/pull/17778

The v1.19.0-pre1 nugets have just been pushed to nuget.org, feel free to try them out and file an issue on github if something doesn't work about the new packages.

Jan, on behalf of the gRPC team