[Suggestion] Rate-Limit, Rate-Remaining, Rate-Reset headers accessible to use

Since the /key endpoint is being depreciated, there is no other way (that I found) to get the key information, other than the `.getKey` or implementing a custom client to get the headers.
My suggestion is to add the ability to get headers when having any reply from the API, E.G `PlayerReply` has a `.getRateLimit`, `.getRateRemaining`, and `.getRateReset`, something that all replies will have.  