feat(admin, admin-ui, medusa-js, medusa-react, medusa): Support Admin Extensions (#4761)

Co-authored-by: Rares Stefan <948623+StephixOne@users.noreply.github.com>
Co-authored-by: Oli Juhl <59018053+olivermrbl@users.noreply.github.com>

packages/admin-ui/webpack.config.dev.ts

@@ -0,0 +1,42 @@
+import { DuplicateReporterPlugin } from "duplicate-dependencies-webpack-plugin"
+import path from "path"
+import { BundleAnalyzerPlugin } from "webpack-bundle-analyzer"
+import { Configuration } from "webpack-dev-server"
+import { getWebpackConfig } from "./src/node/webpack/get-webpack-config"
+
+const getDevServerConfig = () => {
+  const analyzeBundle = process.env.ANALYZE_BUNDLE
+  const analyzeDuplicateDependencies = process.env.ANALYZE_DEPS
+
+  const devConfig = getWebpackConfig({
+    cacheDir: __dirname,
+    dest: path.resolve(__dirname, "build"),
+    entry: path.resolve(__dirname, "ui", "src", "main.tsx"),
+    env: "development",
+    options: {
+      backend: "http://localhost:9000",
+      path: "/",
+    },
+    template: path.resolve(__dirname, "ui", "index.html"),
+  })
+
+  if (analyzeBundle) {
+    devConfig.plugins?.push(new BundleAnalyzerPlugin())
+  }
+
+  if (analyzeDuplicateDependencies === "true") {
+    devConfig.plugins?.push(new DuplicateReporterPlugin())
+  }
+
+  return {
+    ...devConfig,
+    ...{
+      devServer: {
+        port: 7001,
+        historyApiFallback: true,
+      } as Configuration,
+    },
+  }
+}
+
+module.exports = getDevServerConfig()