Rate limit middleware doesn't set headers or provide metadata via interface.

Similar rate limit middleware like [https://github.com/go-chi/httprate](https://github.com/go-chi/httprate) handles automatically setting appropriate `X-Rate-Limit-*` and `Retry-After` headers on a rate limit event which this middleware does not. This is compounded by the `RateLimiterStore` interface not providing a mechanism for returning metadata to set them manually either.