Implement a cli app picodata that accepts parameters and bootstraps a new Picodata cluster.

The app must create a Raft concensus group under the hood and store it's logs somehow (probably in memory for now). Then the app must elect master for each Tarantool replicaset. The information about all instances' desired box.cfg.read_only setting should be stored and spread globally in the Picodata cluster in the global storage on top of the Raft storage.

In the PoC configuration there should be at least 2 replicasets in the cluster and at least 2 instances in each replicaset.