Handle Hub chain fork with chain ID migration

[zale144]

Currently on hubgenesis we save the Hub metadata in its store in the rollapp. For now it is used for the purpose of keeping track of denom metadata that had been registered from the rollapp to the hub. In the unlikely occurrence that the hub chain might do a fork, we should be prepared that its chain ID can change, therefore all the local hub metadata should be migrated to the new KV entry (key is Hub ID).