quic: advertise both quic-draft29 and quic-v1 addresses

[marten-seemann]

This issue assumes that we introduce a new code point for QUIC v1 as suggested in multiformats/multiaddr#145.

For a transition period (6 months?) we should advertise both QUIC draft-29 and QUIC v1. This makes sure that legacy nodes will be able to use QUIC to connect to us for a while. After that, they can still use TCP. Really, they should upgrade their node.

To make this happen, we need to:

• add a new QUIC codepoint for QUIC v1 multiformats/multicodec#298
• make the corresponding change in go-multiaddr
• change transport.Listener.Multiaddr method to return []ma.Multiaddr instead of a single ma.Multiaddr
• use that updated interface to return QUIC draft-29 and QUIC v1 multiaddrs from the QUIC transport
• disable QUIC draft-29 for Webtransport (both for dialing and listening)
• pick the correct version in the QUIC transport for dialing (according to the multiaddr we're dialing)