Connect to all primary network validators on startup

[cam-schultz]

Context and scope
On startup, we manually connect to a small number of primary network validators to bootstrap peer gossip, which eventually connects to all primary network validators. This takes a few rounds of peer gossip, however, which means that signature aggregation requests may fail immediately after startup due to insufficient peer connections. Instead, we could immediately connect to all primary network validators on startup to bypass this restriction.

Discussion and alternatives
Rather than sampling NumBootstrapNodes to connect to, connect to all peers returned by the call to info.Peers on startup.

Open questions
Should this be made the default behavior, or exposed as a config option?