ISPN-4582 JpaStoreTest random failures

* Set threadCount to 1 in surefire plugin
ISPN-4474 ISPN-4473 Get remote events working in compatibility mode

* Fixes both ClassCastExceptions reported in these jiras.
* Adds remote event compatibility tests.
* Refactored remote event assertion code to be sharable between the
Hot Rod client tests and the compatibility tests.