Change from fontawesome to tabler icons (#516)

* Change from fontawesome to tabler icons

- Consistent with the frontend

* Cleanup conflicts

* Use double quotes

* remove unused import

* Update release notes

* Migrate some google icons to tabler icons

* Icon update

* Properly support display of custom icons

* Fix lookup

lib/widget/stock/location_list.dart

@@ -85,7 +85,7 @@ class _PaginatedStockLocationListState extends PaginatedSearchState<PaginatedSto
       title: Text(location.name),
       subtitle: Text(location.pathstring),
       trailing: Text("${location.itemcount}"),
-      leading: location.customIcon,
+      leading: location.customIcon == null ? null : Icon(location.customIcon),
       onTap: () {
         Navigator.push(
           context,