TUN-4597: Add a QUIC server skeleton

- Added a QUIC server to accept streams
- Unit test for this server also tests ALPN
- Temporary echo capability for HTTP ConnectionType

vendor/github.com/lucas-clemente/quic-go/internal/ackhandler/ack_eliciting.go

@@ -0,0 +1,20 @@
+package ackhandler
+
+import "github.com/lucas-clemente/quic-go/internal/wire"
+
+// IsFrameAckEliciting returns true if the frame is ack-eliciting.
+func IsFrameAckEliciting(f wire.Frame) bool {
+	_, isAck := f.(*wire.AckFrame)
+	_, isConnectionClose := f.(*wire.ConnectionCloseFrame)
+	return !isAck && !isConnectionClose
+}
+
+// HasAckElicitingFrames returns true if at least one frame is ack-eliciting.
+func HasAckElicitingFrames(fs []Frame) bool {
+	for _, f := range fs {
+		if IsFrameAckEliciting(f.Frame) {
+			return true
+		}
+	}
+	return false
+}