[ADD] Implement logic for MaxNodeToChurnOutForLowVersion

A new Node Mimir setting is being voted on: MaxNodeToChurnOutForLowVersion

At the moment only one node is churned out for low version each churn. Supporting MaxNodeToChurnOutForLowVersion would allow multiple nodes to churn out for low version.

This will help the network churn out nodes who are slow to update more quickly, allowing for less hold up in upgrading the network to a new version.