Include Host, Port and Scheme in Cache Key

[KLuuKer]

Multi tenant applications may return different content for the same path+query but with a different host header value

Maybe add the Host value to the cache key, or provide a way to customize it using code

[JunTaoLuo]

This would be a simple change here: https://github.com/aspnet/ResponseCaching/blob/dev/src/Microsoft.AspNetCore.ResponseCaching/Internal/ResponseCachingKeyProvider.cs#L55-L57. However, we need to finalize our design for cache keys and address #54.

[JunTaoLuo]

We've decided to make the change without waiting on the cache key redesign.

In addition to the current key, which includes method and path, we will add Scheme, Host and Port to the base cache key.