refactor: revamp devtools page

This commit refactors the development tools page to make it look better. Additionally, it makes small adjustments in the notifications and corrects missing strings from the page.

app/Http/Controllers/AbsenceController.php

@@ -82,7 +82,7 @@ class AbsenceController extends Controller
     {
         $this->authorize('create', Absence::class);
 
-        if ($this->hasActiveRequest(Auth::user())) {
+        if ($this->absenceService->hasActiveRequest(Auth::user())) {
             return redirect()
                 ->back()
                 ->with('error', __('You already have an active request. Cancel it or let it expire first.'));