feature: self-healing network

[Ankesh2004]

There is no proper chunk replication
If a node goes down then its chunk is to be replicated, and if more than K nodes holds a chunk then few nodes can free-up space.

--> Do batch audit of peerHealth and chunks replications
--> There should not be "Stop-the-world" problem

[Ankesh2004]

Batch auditing is done for now ... further optimisations can be done in future (keeping it simple for now)