Improve test coverage of HA CEP by using local queue mechanism

Improve test coverage of HA CEP by using local queue mechanism. Mechanism should be extended in following directions:

1. use of mutable vs. immutable session
2. for mutable session, use of update and deletes (in my test I only have inserts)
3. swicth from leader to replica in the middle of the test to check that the high avaialbility is working as expected