Client: semantic ui -> bootstrap 4 and less -> scss (#8535)

* client: semantic ui -> bootstrap 4 and less -> scss

* start porting components to boostrap

* port header, start porting menu

* port loading screen

* port most of the menu

* port secondary menus

* port guilds and stable

* disable tavern for now, port inbox

* typo

* put back old tavern code

website/client/components/inventory/index.vue

@@ -1,19 +1,14 @@
 <template lang="pug">
 .row
-  .sixteen.wide.column
-    .ui.secondary.menu.center-content
-      router-link.item(:to="{name: 'inventory'}", exact)
-        span(v-once) {{ $t('inventory') }}
-      router-link.item(:to="{name: 'equipment'}")
-        span(v-once) {{ $t('equipment') }}
-      router-link.item(:to="{name: 'stable'}")
-        span(v-once) {{ $t('stable') }}
-
-  .sixteen.wide.column
+  .col-12
+    nav.nav
+      router-link.nav-link(:to="{name: 'inventory'}", exact) {{ $t('inventory') }}
+      router-link.nav-link(:to="{name: 'equipment'}") {{ $t('equipment') }}
+      router-link.nav-link(:to="{name: 'stable'}") {{ $t('stable') }}
+  .col-12
     router-view
 </template>
 
 <script>
-export default {
-};
+export default {};
 </script>