Consider supporting signed peers anouncments

[Nuhvi]

I made a proposal for supporting signed announcements of peers addressed through overlay networks, and for some time few nodes have been supporting that and experimenting with it, and it seems stable, albeit lacking scale. Libtorrent is the largest DHT client (according to my node checking version field in responses), so if you consider this a good feature to add to mainline DHT, implementing it in Libtorrent would be a great step towards its adoption.

Here is one usecase for this proposal rustonbsd/distributed-topic-tracker#18 using the DHT to find peers by their ed25519 keys, and using these keys to connect to these peers through Iroh.

Thanks for the consideration, and please let me know if you have any questions.