Feature/style unification (#420)

* set global icons

* fixes #419

* button style docs

* category/tag page updates

* dynamic router imports

Co-authored-by: hay-kot <hay-kot@pm.me>

frontend/src/pages/Admin/ManageUsers/GroupDashboard.vue

@@ -23,7 +23,7 @@
           <v-card>
             <v-app-bar dark dense color="primary">
               <v-icon left>
-                mdi-account-group
+                {{ $globals.icons.group }}
               </v-icon>
 
               <v-toolbar-title class="headline">