Review/revise 2lc caching design

Review cache isolation, cache region factories, override ISPN default behavior to handle more efficient names, updates to infinispan-hibernate-cache-spi, app configuration choices for choosing different strategies.

• Avoid the ByteString byte length limitation of 255 (https://github.com/infinispan/infinispan/commit/046517fc0829bb0a1768169e549e8e5f6b2b8ea2) in region name prefix + region name as cache key. Also see https://issues.jboss.org/browse/ISPN-9206.
• Enhance the org.jboss.as.jpa.hibernate5.service.WildFlyCustomRegionFactoryInitiator to improve caching for:
  • container managed persistence units
  • non-container-managed persistence unit (e.g. native Hibernate or app calls into javax.persistence.Persistence.createEntityManagerFactory())
  • WildFlyCustomRegionFactoryInitiator cannot start an Infinispan cache by default, should we offer an API/SPI that Spring could implement for specifying the cache (service) to be used for a particular persistence unit? The application could specify the custom API/SPI implementation class via a persistence unit property.
    • Currently, Hibernate defaults the 2lc on but that fails when the Infinispan cache is not automatically started, so WildFlyCustomRegionFactoryInitiator defaults caching off.
    • If this is not possible, then keep the current WildFlyCustomRegionFactoryInitiator logic to default Hibernate caching off, unless the app requests caching via configuration settings.