chore: add 3rd party types in the list of dependencies

Those types are mandatory for TypeScript users.

Related:

- #3690
- microsoft/types-publisher#81 (comment)

package.json

@@ -35,6 +35,9 @@
     "prepack": "tsc"
   },
   "dependencies": {
+    "@types/cookie": "^0.4.0",
+    "@types/cors": "^2.8.8",
+    "@types/node": "^14.14.7",
     "accepts": "~1.3.4",
     "base64id": "~2.0.0",
     "debug": "~4.1.0",
@@ -43,10 +46,7 @@
     "socket.io-parser": "~4.0.1"
   },
   "devDependencies": {
-    "@types/cookie": "^0.4.0",
-    "@types/cors": "^2.8.7",
     "@types/mocha": "^8.0.3",
-    "@types/node": "^14.11.2",
     "babel-eslint": "^10.1.0",
     "eslint": "^7.9.0",
     "eslint-config-prettier": "^6.11.0",