ISPN-4580 Refactor BaseStoreTest

...and its subclasses

* Remove duplicated code
* replace assert keyword by AssertJUnit methods
* use a mock cache in the stores to test
ISPN-4581 Memory leak when H2 is used

* clear the cache before killing the cache manager
ISPN-4520 JdbcBinaryStoreTest.testLoadAndStoreWithLifespanAndIdle random failures

* Use a custom TimeService to trigger the expiration