asserts that socket addresses set in new_with_external_ip are valid

new_with_external_ip silently ignores errors when setting socket
addresses which makes it harder to catch bugs:
https://github.com/solana-labs/solana/blob/7beeb8310/gossip/src/cluster_info.rs#L3054-L3063

gossip/src/cluster_info.rs

@@ -3051,16 +3051,19 @@ impl Node {
             0u16,        // shred_version
         );
         let addr = gossip_addr.ip();
-        let _ = info.set_gossip((addr, gossip_port));
-        let _ = info.set_tvu((addr, tvu_port));
-        let _ = info.set_tvu_quic((addr, tvu_quic_port));
-        let _ = info.set_tpu(public_tpu_addr.unwrap_or_else(|| SocketAddr::new(addr, tpu_port)));
-        let _ = info.set_tpu_forwards(
+        info.set_gossip((addr, gossip_port)).unwrap();
+        info.set_tvu((addr, tvu_port)).unwrap();
+        info.set_tvu_quic((addr, tvu_quic_port)).unwrap();
+        info.set_tpu(public_tpu_addr.unwrap_or_else(|| SocketAddr::new(addr, tpu_port)))
+            .unwrap();
+        info.set_tpu_forwards(
             public_tpu_forwards_addr.unwrap_or_else(|| SocketAddr::new(addr, tpu_forwards_port)),
-        );
-        let _ = info.set_tpu_vote((addr, tpu_vote_port));
-        let _ = info.set_serve_repair((addr, serve_repair_port));
-        let _ = info.set_serve_repair_quic((addr, serve_repair_quic_port));
+        )
+        .unwrap();
+        info.set_tpu_vote((addr, tpu_vote_port)).unwrap();
+        info.set_serve_repair((addr, serve_repair_port)).unwrap();
+        info.set_serve_repair_quic((addr, serve_repair_quic_port))
+            .unwrap();
         trace!("new ContactInfo: {:?}", info);
 
         Node {