The replication scenario tests were broken into separate
parts to facilitate parallel runs in the gate.
The verify_data helper was also enhanced to retry so that
arbitrary sleeps are no longer necessary to ensure that
data has time to replicate.
Additional data was also added/verified once the replication
network is back to its original configuration.
Partial-Bug: #1571092
Change-Id: I78bc945b36b1abba19e102cc2742984bd2375513