Switch to new gRPC package

[ejizba]

Per this readme and this blogpost, the Grpc.Net.Client nuget package is now the recommended gRPC implementation for .NET/C# as opposed to the Grpc.Core package. The old package is currently in maintenance mode and will be deprecated in May 2022

[Francisco-Gamino]

Hello @michaelpeng36 -- I am assigning this to you since you are already working on it.