Build: Fix failing CSS asset paths (#95380)

* build(webpack): set publicpath and process urls to resolve assets correctly

* build(webpack): add back --progress to build

* Add local cdn

(cherry picked from commit 7a19523fa476fd5ff2d7669d116f5be462b100f5)

* chore(devenv): fix local_cdn path in ngnix conf

* chore(codeowners): add frontend-ops as owners of local_cdn docker block

---------

Co-authored-by: Andreas Christou <andreas.christou@grafana.com>

scripts/webpack/sass.rule.js

@@ -7,7 +7,12 @@ module.exports = function (options) {
   return {
     test: /\.(sa|sc|c)ss$/,
     use: [
-      MiniCssExtractPlugin.loader,
+      {
+        loader: MiniCssExtractPlugin.loader,
+        options: {
+          publicPath: './',
+        },
+      },
       {
         loader: 'css-loader',
         options: {