VLESS Encryption: Switch to "probability-from-to" format for customizable 1-RTT padding parameters

See https://github.com/XTLS/Xray-core/pull/5067#issue-3361308276 for details

proxy/vless/encryption/client.go

@@ -22,8 +22,8 @@ type ClientInstance struct {
 	RelaysLength  int
 	XorMode       uint32
 	Seconds       uint32
-	PaddingLens   [][2]int
-	PaddingGaps   [][2]int
+	PaddingLens   [][3]int
+	PaddingGaps   [][3]int
 
 	RWLock sync.RWMutex
 	Expire time.Time