In a distributed cache stale entries are not removed from the store

This is a follow-up on ISPN-11116. It's wrong for invalidation commands to load the previous value from the store, but we also have the opposite problem: in a distributed cache, when a node loses some segments and the store is not segmented, we use an InvalidateCommand to remove stale entries, and it doesn't actually remove any entries from the store.

Instead of keeping InvalidateCommand as is and finding another solution for removing stale segments, we could change InvalidateCommand to also remove entries from private stores.

Invalidation mode is very unlikely to be used with private stores, but we don't actually prohibit it, so it's better for invalidation mode as well if InvalidateCommand removed entries from the private stores and ignored the shared stores. The only problem remaining is to actually optimize CacheLoaderInterceptor so that it doesn't load the previous value unless there is a listener.