Password Reset: grpc for getting personId from email address

[kevinmichaelchen]

To see how we can decompose the original, monolithic Rampart into services, see: https://gist.github.com/kevinmichaelchen/6614b0799f09144ef348b3cb9a871820

For a good gRPC example, see https://github.com/grpc/grpc-go/blob/master/examples/helloworld/helloworld/helloworld.proto