Lock down replication factor after cluster has been created

[purplefox]

We should prevent user from changing replication factor after cluster has been created. We can do this in a similar way to how we do with number of shards - i.e. storing the number in the database itself.

[mohsalsaleem]

Hello @purplefox, are you referring to this shards check implementation?

[purplefox]

Yes a similar check