ISPN-3290 Redesign CacheStore API

* upgraded to accommodate the new API changes in core
ISPN-3290 Redesign CacheStore API

* the root package name for all the stores is persistence
ISPN-3290 Redesign CacheStore API

* added unit test for Parallel iteration of entries
ISPN-3489 Use HttpComponents 4.x instead of the old httpclient 3.x libraries