MINOR: quic: implement cc-algo server keyword

MINOR: quic: implement cc-algo server keyword

Extend QUIC server configuration so that congestion algorithm and
maximum window size can be set on the server line. This can be achieved
using quic-cc-algo keyword with a syntax similar to a bind line.

This should be backported up to 3.3 as this feature is considered as
necessary for full QUIC backend support. Note that this relies on the
serie of previous commits which should be picked first.