feat: implement BackButton component for consistent navigation

- Added BackButton component to standardize back navigation across pages.
- Integrated BackButton into various pages, replacing custom back buttons for consistency.
- Updated PageHeader to accept backTo prop for displaying BackButton when navigating from subpages.
- Created useGoBack hook to handle navigation logic, determining whether to go back in history or redirect to a fallback page.
- Added tests for BackButton and its integration with PageHeader to ensure expected behavior.

assets/admin/pages/RepresentationBlogFormPage.tsx

@@ -93,6 +93,7 @@ export default function RepresentationBlogFormPage() {
   return (
     <div>
       <PageHeader
+        backTo="/admin/representation-blogs"
         title={isEdit ? 'ویرایش مقاله' : 'نوشتن مقالهٔ جدید'}
         breadcrumbs={[{ label: 'وبلاگ من', to: '/admin/representation-blogs' }, { label: isEdit ? 'ویرایش' : 'جدید' }]}
       />