quic datagram

[turuslan]

Expose api for unreliable datagram over quic

auto injector = libp2p::injector::makeHostInjector(
  libp2p::injector::enableDatagram(),
  ...
);

injector.create<libp2p::OnDatagramConfigPtr>()->on_datagram = [](
  std::shared_ptr<connection::CapableConnection> connection,
  qtils::ByteVec message
) {
  ...
};

auto cancelable = connection->sendDatagram(message);