kad: migrate to quick-protobuf-codec crate

[thomaseizinger]

In /misc we have the quick-protobuf-codec crate which makes working with protobuf structs over streams quite easy as you only need to construct a asynchronous_codec::Framed type and can read and write full protobuf messages on any Async{Read,Write}.

We should make use of this in libp2p-kad.

See https://docs.rs/quick-protobuf-codec.

Previous tracking issue: #2500

[0xcrust]

@thomaseizinger I'd love to give this an attempt if you don't mind

[thomaseizinger]

@thomaseizinger I'd love to give this an attempt if you don't mind

Great! I've assigned you! If you look through the tracking issue (#2500) you should be able to find several links to PRs where we've already done something similar! :)

Feel free to open a draft PR at any time if you need help.