UDP/QUIC/Http3 quiche::h3 Client/Connector integration

[hargut]

Overview

The PR builds on top of #514 and integrates Quiche/Http3 with pingora-core on the client side. It provides another part to integrate QUIC support in pingora.

During the works several common client/server areas have been unified and modelled for according reuse. Further some issues with the listener implementation had been identified and fixed.

For additional details please refer to #514 and #95.

Have a nice week and stay safe! :smiley:

Kind regards, Harald