✨(frontend) add tabs for mail domain page (#466)

Currently, it is complicated to understand the navigation between mailbox
management and role management for an email domain.
This is why we add tabs with explicit naming

src/frontend/apps/desk/next.config.js

@@ -1,3 +1,5 @@
+const path = require('path');
+
 /** @type {import('next').NextConfig} */
 const nextConfig = {
   output: 'export',
@@ -5,6 +7,9 @@ const nextConfig = {
   images: {
     unoptimized: true,
   },
+  sassOptions: {
+    includePaths: [path.join(__dirname, 'src')],
+  },
   compiler: {
     // Enables the styled-components SWC transform
     styledComponents: true,