[PM-10261] Migrate from gulp to webpack (#4569)

* Migrate from gulp to bootstrap

* Remove auto build since it breaks tests

src/Admin/webpack.config.js

@@ -0,0 +1,66 @@
+const path = require("path");
+const MiniCssExtractPlugin = require("mini-css-extract-plugin");
+
+const paths = {
+  assets: "./wwwroot/assets/",
+  sassDir: "./Sass/",
+};
+
+/** @type {import("webpack").Configuration} */
+module.exports = {
+  mode: "production",
+  devtool: "source-map",
+  entry: {
+    site: [
+      path.resolve(__dirname, paths.sassDir, "site.scss"),
+
+      "popper.js",
+      "bootstrap",
+      "jquery",
+      "font-awesome/css/font-awesome.css",
+      "toastr",
+      "toastr/build/toastr.css",
+    ],
+  },
+  output: {
+    clean: true,
+    path: path.resolve(__dirname, paths.assets),
+  },
+  module: {
+    rules: [
+      {
+        test: /\.(sa|sc|c)ss$/,
+        use: [MiniCssExtractPlugin.loader, "css-loader", "sass-loader"],
+      },
+      {
+        test: /.(ttf|otf|eot|svg|woff(2)?)(\?[a-z0-9]+)?$/,
+        exclude: /loading(|-white).svg/,
+        generator: {
+          filename: "fonts/[name].[contenthash][ext]",
+        },
+        type: "asset/resource",
+      },
+
+      // Expose jquery and toastr globally so they can be used directly in asp.net
+      {
+        test: require.resolve("jquery"),
+        loader: "expose-loader",
+        options: {
+          exposes: ["$", "jQuery"],
+        },
+      },
+      {
+        test: require.resolve("toastr"),
+        loader: "expose-loader",
+        options: {
+          exposes: ["toastr"],
+        },
+      },
+    ],
+  },
+  plugins: [
+    new MiniCssExtractPlugin({
+      filename: "[name].css",
+    }),
+  ],
+};