re-add jquery and select2 used in app.js

core/admin/package.json

@@ -17,11 +17,13 @@
     "babel-loader": "^8.0.6",
     "css-loader": "^2.1.1",
     "expose-loader": "^0.7.5",
+	"jquery": "^3.6.0",
     "less": "^3.13.1",
     "less-loader": "^5.0.0",
     "mini-css-extract-plugin": "^1.2.1",
     "node-sass": "^4.13.1",
     "sass-loader": "^7.3.1",
+	"select2": "^4.0.13",
     "url-loader": "^2.3.0",
     "webpack": "^4.33.0",
     "webpack-cli": "^3.3.12"