RFC: Use QUIC over UDP instead of TCP

[damip]

Instead of using TCP, or as a complement, this RFC proposes to use QUIC over UDP: https://en.wikipedia.org/wiki/QUIC

The advantages of using QUIC are the following:

• can bypass NATs via UDP hole punching: https://en.wikipedia.org/wiki/UDP_hole_punching
• can handle encryption and authentication natively

Different benchmarks give mixed results on performance vs TCP:

• https://github.com/Shenggan/quic_vs_tcp
• https://www.fastly.com/blog/measuring-quic-vs-tcp-computational-efficiency
• https://www.scirp.org/journal/paperinformation.aspx?paperid=113892
• https://blog.apnic.net/2018/01/29/measuring-quic-vs-tcp-mobile-desktop/
• https://medium.com/@the.real.yushuf/benchmarking-quic-1fd043e944c7
• https://medium.com/codavel-blog/quic-vs-tcp-tls-and-why-quic-is-not-the-next-big-thing-d4ef59143efd

The disvantages of QUIC over TCP:

• in some security contexts, UDP connections can be more limited than outgoing TCP
• not native: requires an userspace library
• probably less hardware acceleration (?)

Some rust lib: https://github.com/quinn-rs/quinn