Add ShadowTLS protocol v3

transport/shadowtls/config_119.go

@@ -0,0 +1,16 @@
+//go:build !go1.20
+
+package shadowtls
+
+import sTLS "github.com/sagernet/sing-box/transport/shadowtls/tls_go119"
+
+type (
+	sTLSConfig          = sTLS.Config
+	sTLSConnectionState = sTLS.ConnectionState
+	sTLSConn            = sTLS.Conn
+)
+
+var (
+	sTLSCipherSuites = sTLS.CipherSuites
+	sTLSClient       = sTLS.Client
+)