Drop some boilerplate in lighthouse_network

[dapplion]

Description

There are some comments that do not provide any new information and are just noise

https://github.com/sigp/lighthouse/blob/3b42c8c5930648c5bcd8ee04cdadb75ad73a045f/beacon_node/lighthouse_network/src/rpc/methods.rs#L434-L441

https://github.com/sigp/lighthouse/blob/3b42c8c5930648c5bcd8ee04cdadb75ad73a045f/beacon_node/lighthouse_network/src/rpc/protocol.rs#L235-L239

https://github.com/sigp/lighthouse/blob/3b42c8c5930648c5bcd8ee04cdadb75ad73a045f/beacon_node/lighthouse_network/src/rpc/rate_limiter.rs#L84-L89

https://github.com/sigp/lighthouse/blob/3b42c8c5930648c5bcd8ee04cdadb75ad73a045f/beacon_node/lighthouse_network/src/service/api_types.rs#L37-L41

Matches like this could group conceptually protocol and use A | B | C => return

https://github.com/sigp/lighthouse/blob/3b42c8c5930648c5bcd8ee04cdadb75ad73a045f/beacon_node/lighthouse_network/src/peer_manager/mod.rs#L601-L614