We extend quicserver so that it can handle multiple requests with an
HTTP request on each one. If a uni-directional stream comes in we create
a uni-directional stream for the response
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/21765)