Modification of agent version for Lodestar

[philknows]

Reference: https://github.com/ChainSafe/lodestar/issues/4465

Lodestar is looking to modify the agent version gossiped from the default libp2p string js-libp2p/0.36.2 to lodestar/version. We are requesting an update to your crawler on how you identify Lodestar nodes for better tracking and referencing of Lodestar peers on the network for debug/stats purposes.

[cortze]

Hey @philknows thanks for letting us know about the change! I'm afk until Monday, but will take care of it 😁

[cortze]

Hey @philknows , I also discovered that Grandine also upgraded from rust-libp2p/{version} to Grandine-{version}. Updating them both in this commit

[cortze]

Closed with #50