feature(raft_config): Add config file for raft experimental
feature(raft_config): Add config file for raft experimental

Added new config file which enable the raft feature in experimental mode.

scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests