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

app/Models/UserBranch.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Modules\Usermanagement\Models;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Modules\Usermanagement\Models\User;
+use Modules\Basicdata\Models\Branch;
+
+// use Modules\Usermanagement\Database\Factories\UserBranchFactory;
+
+class UserBranch extends Model
+{
+    use HasFactory;
+
+    /**
+     * The attributes that are mass assignable.
+     */
+    protected $table = 'user_branches';
+    protected $fillable = [
+        'user_id',
+        'branch_id',
+    ];
+
+    public function user()
+    {
+        return $this->belongsTo(User::class);
+    }
+
+    public function branch()
+    {
+        return $this->belongsTo(Branch::class);
+    }
+}