feat(gateway): 优化gateway相关功能

internal/gateway/token.go

@@ -0,0 +1,15 @@
+package gateway
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+)
+
+// NewToken 生成一个消息网关的访问 Token
+func NewToken() (string, error) {
+	b := make([]byte, 32)
+	if _, err := rand.Read(b); err != nil {
+		return "", err
+	}
+	return "gw_" + hex.EncodeToString(b), nil
+}