raft: replication test: parametrize snapshots
raft: replication test: parametrize snapshots

Snapshots and persisted snapshots created per test instead of globals.

Signed-off-by: Alejo Sanchez <004be06a28e38b437b038f9b5c0b9f5758b792e9@scylladb.com>

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla