refactor: admin system info to vue3 comp api

ux/src/pages/AdminGeneral.vue

@@ -589,8 +589,8 @@ async function save () {
       type: 'positive',
       message: t('admin.general.saveSuccess')
     })
-    if (adminStore.currentSiteId === siteStore.id) {
     await adminStore.fetchSites()
+    if (adminStore.currentSiteId === siteStore.id) {
       siteStore.$patch({
         title: state.config.title,
         description: state.config.description,

ux/src/router/routes.js

@@ -48,7 +48,7 @@ const routes = [
       // { path: 'extensions', component: () => import('../pages/AdminExtensions.vue') },
       // { path: 'mail', component: () => import('../pages/AdminMail.vue') },
       // { path: 'security', component: () => import('../pages/AdminSecurity.vue') },
-      // { path: 'system', component: () => import('../pages/AdminSystem.vue') },
+      { path: 'system', component: () => import('../pages/AdminSystem.vue') },
       // { path: 'utilities', component: () => import('../pages/AdminUtilities.vue') },
       // { path: 'webhooks', component: () => import('../pages/AdminWebhooks.vue') },
       { path: 'flags', component: () => import('../pages/AdminFlags.vue') }