ISPN-4444 After state transfer, a node is able to read keys it no longer...

... owns from its data container

* mark the keys stored as L1
* this avoid read the keys that are going to be invalidated during the ST

https://issues.jboss.org/browse/ISPN-4444
Now that you have `L1InternalCacheEntry`, do you still need `L1Metadata`?