Rewrite Hibernate2ndLevelCacheIntegrationTests to use ehcache

[snicoll]

I've just noticed that the rest of the hibernate tests using JCache were working because ehcache is preferred. This particular test is the only one that uses Hazelcast and it doesn't really matter what the cache provider is.

Unfortunately, not configuring hazelcast means the client is trying to connect to a server and that leads to each test left hanging until that happens.