Add ShopModel and integrate with ProductModel

- Created ShopModel with fields for shop name, description, and user association.
- Updated ProductModel to include a foreign key relationship with ShopModel.
- Added admin interface for ShopModel with search functionality.
- Created migrations for ShopModel and its integration with ProductModel.

backend/core/settings/unfold_conf.py

@@ -107,6 +107,11 @@ UNFOLD = {
                         "link": reverse_lazy("admin:order_ordermodel_changelist"),
                         "badge": "utils.admin.admin_pending_count",
                     },
+                    {
+                        "title": _("فروشگاه ها"),
+                        "icon": "storefront",
+                        "link": reverse_lazy("admin:account_shopmodel_changelist"),
+                    },
                 ],
             },