add express-validator and xss

packages/remark-lsx/package.json

@@ -38,9 +38,11 @@
     "@growi/ui": "link:../ui",
     "escape-string-regexp": "^4.0.0",
     "express": "^4.20.0",
+    "express-validator": "^6.14.0",
     "http-errors": "^2.0.0",
     "mongoose": "^6.11.3",
-    "swr": "^2.2.2"
+    "swr": "^2.2.2",
+    "xss": "^1.0.15"
   },
   "devDependencies": {
     "eslint-plugin-regex": "^1.8.0",