message: Add ack and loss trace for Quic Copa
  Summary: as title, simple diff
diff: #include <quic/common/TimeUtil.h>
  #include <quic/congestion_control/CongestionControlFunctions.h>
  #include <quic/logging/QLoggerConstants.h>
  +#include <quic/logging/QuicLogger.h>
  namespace quic {
  @@ -129,9 +130,11 @@ void Copa::onPacketAckOrLoss(
  folly::Optional<LossEvent> loss) {
  if (loss) {
  onPacketLoss(*loss);
  + QUIC_TRACE(copa_loss, conn_, cwndBytes_, bytesInFlight_);
  }
  if (ack && ack->largestAckedPacket.hasValue()) {
  onPacketAcked(*ack);
  + QUIC_TRACE(copa_ack, conn_, cwndBytes_, bytesInFlight_);
  }
  }
  