MWPW-149124 Improve Focus Page for Performance Improvement Tiger Team (…

…#2391)

* Optimize icons  .css and .svg loading

* Preload helpers.js

* Remove dependency on helpers.js

libs/features/icons/icons.js

@@ -4,9 +4,7 @@ let fetched = false;
 async function getSVGsfromFile(path) {
   /* c8 ignore next */
   if (!path) return null;
-  const { customFetch } = await import('../../utils/helpers.js');
-  const resp = await customFetch({ resource: path, withCacheRules: true })
-    .catch(() => ({}));
+  const resp = await fetch(path);
   /* c8 ignore next */
   if (!resp.ok) return null;
   const miloIcons = {};

libs/utils/utils.js

@@ -712,9 +712,9 @@ function decorateHeader() {
 async function decorateIcons(area, config) {
   const icons = area.querySelectorAll('span.icon');
   if (icons.length === 0) return;
-  const { miloLibs, codeRoot } = config;
-  const base = miloLibs || codeRoot;
-  await new Promise((resolve) => { loadStyle(`${base}/features/icons/icons.css`, resolve); });
+  const { base } = config;
+  loadStyle(`${base}/features/icons/icons.css`);
+  loadLink(`${base}/img/icons/icons.svg`, { rel: 'preload', as: 'fetch', crossorigin: 'anonymous' });
   const { default: loadIcons } = await import('../features/icons/icons.js');
   await loadIcons(icons, config);
 }