Geo: Feature Flags (Flipper) state is cached in Redis

We need to propagate feature flag changes to secondary nodes in order to clear cache on these nodes as well.

We should investigate other cache propagation issues and see if we need to provide a generic cache invalidation replication log. There is the opportunity for optimizations here:

• We can cleanup the whole cache when resuming from a paused replication
• We don’t need to process any cleanup log when starting a new node

To do so, we may want to store this type of replication log in a different table so we can “skip” the cursor position when an optimization can be done according to the situations described above.