Add landmark for the cookie banner and update its links color (#25823)

* Update cookie banner link color

* Add landmark for the cookie banner

GitOrigin-RevId: 9500cdfd7ddacbc2442680ed477ca1ac793720f7

services/web/app/views/_cookie_banner.pug

@@ -1,5 +1,5 @@
-.cookie-banner.hidden-print.hidden
+section.cookie-banner.hidden-print.hidden(aria-label="Cookie banner")
     .cookie-banner-content We only use cookies for essential purposes and to improve your experience on our site. You can find out more in our <a href="/legal#Cookies">cookie policy</a>.
     .cookie-banner-actions
         button(type="button" class="btn btn-link btn-sm" data-ol-cookie-banner-set-consent="essential") Essential cookies only
-        button(type="button" class="btn btn-primary btn-sm" data-ol-cookie-banner-set-consent="all") Accept all cookies
+        button(type="button" class="btn btn-primary btn-sm" data-ol-cookie-banner-set-consent="all") Accept all cookies

services/web/frontend/stylesheets/bootstrap-5/components/footer.scss

@@ -395,6 +395,11 @@ footer.site-footer {
       white-space: nowrap;
       padding-top: var(--spacing-00);
     }
+
+    .cookie-banner-content a,
+    .cookie-banner-actions .btn-link {
+      color: var(--link-ui);
+    }
   }
 }