Review pubsub libp2p settings across lotus for high throughput messaging

[masih]

So far gossipsub in filecoin has been used for a small message propagation rate. With F3 this is increased by may orders of magnitude, where the rate is a factor of the number of F3 participants.

Review libp2p settings and pubsub settings to tune for the new normal: F3 high-rate message passing.

[masih]

Specifically, read through gossipsub security extensions before making changes.