feat: add native Webtransport transport

[mxinden]

Description

Work in progress

Here to prevent two implementations to emerge in parallel.

Notes & open questions

Fixes #2993.

Change checklist

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• A changelog entry has been made in the appropriate crates

[oblique]

I'm wondering. With the current libp2p API, will it be possible to have Quic and WebTransport listening on the same port?

[thomaseizinger]

I'm wondering. With the current libp2p API, will it be possible to have Quic and WebTransport listening on the same port?

I don't think we will able to do that straight away. We need to share a UDP socket between the two for that. I've been thinking about how to offer this and it might be possible if we allow to pass some (shared) abstraction over a socket into each transport.

[mxinden]

I'm wondering. With the current libp2p API, will it be possible to have Quic and WebTransport listening on the same port?

@oblique in case it is of some interest, here is the corresponding work on the go-libp2p side libp2p/go-libp2p#1759.