test(p2p): cover peer, utils, quic_upgrade, force_direct, bootnode

[iamquang95]

Fix #620

• peer.rs — replaced the three #[ignore]d todo!() stubs with ports of charon's p2p/peer_test.go: new_tcp_host, new_quic_host, verify_p2p_key_accepts_cluster_keys, peer_id_key. Plus new_host_without_listen_addrs, charon's own assertion that both node types build from an empty config (outgoing-only nodes).
• utils.rs — address classifiers with positive/negative multiaddrs, addr_type/addr_protocol, filter_direct_quic_addrs, has_direct_{quic,tcp}_conn, and a verbatim port of charon's TestFilterAdvertisedAddrs table.
• quic_upgrade.rs — QuicUpgradeBackoff table test (1 → doubling → 512 cap), should_skip countdown, per-peer isolation, clear_backoff.
• force_direct.rs — the forcing path plus every skip condition, including the all-relay guard. Asserts the selected addresses, not just the dialled peer ID.
• proto.rs — varint framing round-trip across the 1→2 byte prefix boundary, sequential frames, oversize and truncation.
• bootnode.rs — multi_addr_from_enr_str: port mapping table, EnrNoIp, EnrNoPort, garbage inputs.

33 tests added; no #[ignore] or todo!() left in crates/p2p.

[emlautarom1]

Only one potential issue by relying on the debug format of an external type (a bit too brittle). The deviation is minor considering that at the end of the day the ordering does not matter since it's consumed by a hashset, but we can cleanup the code by matching the exact behavior. Rest are nits.