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/RepresentationDetailPage.tsx

@@ -184,6 +184,7 @@ export default function RepresentationDetailPage() {
     return (
       <div>
         <PageHeader
+        backTo="/admin/representations"
           title="جزئیات نماینده"
           breadcrumbs={[
             { label: 'داشبورد', to: '/admin/dashboard' },
@@ -206,6 +207,7 @@ export default function RepresentationDetailPage() {
     return (
       <div>
         <PageHeader
+        backTo="/admin/representations"
           title="نماینده یافت نشد"
           breadcrumbs={[
             { label: 'داشبورد', to: '/admin/dashboard' },
@@ -224,6 +226,7 @@ export default function RepresentationDetailPage() {
   return (
     <div>
       <PageHeader
+        backTo="/admin/representations"
         title={name}
         breadcrumbs={[
           { label: 'داشبورد', to: '/admin/dashboard' },