gossip: use all PeerIds per AuthorityId

[ordian]

Even after #4295, in gossip protocols, we'd still use the first PeerId found in the mapping

polkadot/node/network/bridge/src/lib.rs

Line 589 in d7846bb

let addr = get_peer_id_by_authority_id(

this helper function should be removed:

polkadot/node/network/bridge/src/network.rs

Lines 205 to 209 in d7846bb

	/// We assume one `peer_id` per `authority_id`.
	pub async fn get_peer_id_by_authority_id<AD: AuthorityDiscovery>(
	authority_discovery: &mut AD,
	authority: AuthorityDiscoveryId,
	) -> Option<PeerId> {