Implement cache sets using publishers

Currently cache sets are implemented using EntrySetCommand and KeySetCommand, and because there is no guaranteed cache-level CacheSet implementation, each interceptor implements the full CacheSet interface.

We could simplify the code by making the interceptors implement a simpler interface, with only the localPublisher(segment/segments), with a single implementation of CacheSet at the cache level that delegates regular operations to the cache, and iteration to DistributedCacheStream.