Make esbuild/webpack work with .storybook/preview.js

This js file uses JSX syntax. We have to treat it separately. Including
loader: jsx in the existing loader makes it not work with TypeScript
so split in into two different loaders for JSX/TS/TSX and JS.

webpack.config.js

@@ -78,12 +78,20 @@ module.exports = (_env, argv) => {
     module: {
       rules: [
         {
-          test: /\.(js|jsx|ts|tsx)$/,
+          test: /\.(jsx|ts|tsx)$/,
           loader: "esbuild-loader",
           options: {
             target: resolveToEsbuildTarget(browserslist())
           }
         },
+        {
+          test: /\.js$/,
+          loader: "esbuild-loader",
+          options: {
+            loader: "jsx",
+            target: resolveToEsbuildTarget(browserslist())
+          }
+        },
         // We consume svg files from dpl-design-system package
         {
           test: /\.svg$/,