feat(types): Add gRPC Richer Error Model support (BadRequest)

[flemosr]

Motivation

The gRPC Richer Error Model is quite useful to send additional feedback to clients, and is supported by many gRPC libraries in other languages.

Solution

This PR is the first step to add richer error model support to tonic-types, as per #1060. It introduces the WithErrorDetails trait and adds support to the BadRequest standard error message type.