kad: emit ToSwarm::NewExternalAddrOfPeer

[thomaseizinger]

Description

With #4371 merged, we have the foundation of #4302 implemented.

libp2p-kad needs to be extended to emit this new event whenever it discovers a new address through the DHT.

Motivation

Other behaviours should be able to learn the addresses discovered by kademlia.

Current Implementation

Only kademlia knows about its discovered addresses.

Are you planning to do it yourself in a pull request ?

No

[1010adigupta]

would like to work on this

[1010adigupta]

would work on mDNS and DHT simultaneously, you can assign me this as well

[thomaseizinger]

would work on mDNS and DHT simultaneously, you can assign me this as well

Make them two PRs please! :)

[justcode740]

unsure whether this one is taken but seem prev one has made such claim and not submit pattern in some other repo couple times..

[thomaseizinger]

You are welcome to work on this too!

[blacktoast]

Hi, do you mind if I try to do this?

I know a little bit of Rust, but this is my first time contributing to a p2p related library, so if you don't mind, is there any code or documentation that would help me solve this issue?