Infinispan binary store should be able to use the main content cache

The Infinispan cache currently uses two separate caches: one for the (chunked) data, and one for the metadata. In most configurations, these caches should be distinct and configured differently (they have different access patterns and size requirements).

But in very small repositories that don't store very many BINARY values, it may be desirable to still use the Infinispan binary store, but managing separate caches may be more overhead than desired. So, it should be possible to configure ModeShape repositories that fit this specific use case to use one Infinispan cache for the content and for the binary storage.

It is not quite possible to do this now because of the way the Infinispan binary store uses the same keys for the metadata as for the data. By changing the keys used for metadata slightly, we can make this special case possible.