feat: nameserver-policy support domain-set, reduce domain-set memory usage

common/utils/strings.go

@@ -0,0 +1,8 @@
+package utils
+func Reverse(s string) string {
+	a := []rune(s)
+	for i, j := 0, len(a)-1; i < j; i, j = i+1, j-1 {
+		a[i], a[j] = a[j], a[i]
+	}
+	return string(a)
+}