feat: Implement user-branch relationship and update user management views

- Added a many-to-many relationship between users and branches in User model.
- Updated user creation and editing views to support multiple branch selection.
- Modified user index view to display associated branches.
- Created UserBranch model to manage user-branch associations.
- Added migration for user_branches table with foreign key constraints.
- Implemented seeder to populate user_branches based on existing user branch data.

Run this command:
- php artisan migrate
- php artisan module:seed Usermanagement --class=UserBranchesSeeder

database/seeders/UserBranchesSeeder.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace Modules\Usermanagement\Database\Seeders;
+
+use Illuminate\Database\Seeder;
+use Illuminate\Support\Facades\DB;
+use Modules\Usermanagement\Models\User;
+
+class UserBranchesSeeder extends Seeder
+{
+    /**
+     * Run the database seeds.
+     */
+    public function run(): void
+    {
+        $users = User::all();
+
+        foreach ($users as $user) {
+            if ($user->branch_id) {
+                $exists = DB::table('user_branches')
+                    ->where('user_id', $user->id)
+                    ->where('branch_id', $user->branch_id)
+                    ->exists();
+
+                if (!$exists) {
+                    DB::table('user_branches')->insert([
+                        'user_id' => $user->id,
+                        'branch_id' => $user->branch_id,
+                        'created_at' => now(),
+                        'updated_at' => now(),
+                    ]);
+                }
+            }
+        }
+
+        $this->command->info('User branches seeded successfully.');
+    }
+}