Include standard details payloads in "well-known" protobuf types known by grpcurl

The standard details payloads are commonly used for error details. This is prescribed by AIP-193: Errors. These message types are not likely to be referenced from service definitions, and are therefore unlikely to be available from server reflection. Having these be "built-in" to grpcurl would allow them to be resolved when grpcurl receives an error status while still using server reflection.

Related to #152