FAB-15042 Mig-v1 cleanup #1

In preparation to the alternative migration design (v2),
revert some of the commits already merged.

Kafka to Raft migration v1 - cleanup #1
Remove integration test

Clean commits:
05485b9
5d98705

Change-Id: I9f22fd89534da57f2efcb417493c33cfa409039c
Signed-off-by: Yoav Tock <tock@il.ibm.com>

Author: tock-ibm