Better exception message

[mayuki]

On the client side, clarify the message of exceptions thrown by StreamingHub handler.

Before

Unhandled Exception with IsReturnExceptionStackTraceInErrorDetail=true

Unhandled exception. Grpc.Core.RpcException: System.InvalidOperationException: shinu
   at MyApp.Server.Hubs.TimerHub.SetAsync(TimeSpan interval)
   ...

Unhandled Exception with IsReturnExceptionStackTraceInErrorDetail=false

Unhandled exception. Grpc.Core.RpcException: Exception of type 'Grpc.Core.RpcException' was thrown.
   at MagicOnion.Client.StreamingHubClientBase`2.WriteMessageWithResponseAsync[TRequest,TResponse](Int32 methodId, TRequest message)
   ...

ReturnStatusException

Unhandled exception. Grpc.Core.RpcException: Exception of type 'Grpc.Core.RpcException' was thrown.
   at MagicOnion.Client.StreamingHubClientBase`2.WriteMessageWithResponseAsync[TRequest,TResponse](Int32 methodId, TRequest message)
   ...

After

Unhandled Exception with IsReturnExceptionStackTraceInErrorDetail=true

Unhandled exception. Grpc.Core.RpcException: An error occurred while processing handler 'ITimerHub/SetAsync'.
System.InvalidOperationException: shinu
   at MyApp.Server.Hubs.TimerHub.SetAsync(TimeSpan interval)
   ...

Unhandled Exception with IsReturnExceptionStackTraceInErrorDetail=false

Unhandled exception. Grpc.Core.RpcException: Status(StatusCode="Internal", Detail="An error occurred while processing handler 'ITimerHub/SetAsync'.")
   at MagicOnion.Client.StreamingHubClientBase`2.WriteMessageWithResponseAsync[TRequest,TResponse](Int32 methodId, TRequest message)
   ...

ReturnStatusException

Unhandled exception. Grpc.Core.RpcException: Status(StatusCode="AlreadyExists", Detail="Sudeniaru")
   at MagicOnion.Client.StreamingHubClientBase`2.WriteMessageWithResponseAsync[TRequest,TResponse](Int32 methodId, TRequest message)
   ...

[neuecc]

Good!!!

[ShyDoki]

Good!!!