Add validators and services for Product Galleries and Product Tags

- Implemented Create, Delete, Get, and Update validators for Product Galleries.
- Added Create, Delete, Get, and Update validators for Product Tags.
- Created service classes for handling Discount Categories, Discount Orders, Discount Products, Discount Shopping Cart, Product Categories, Product Galleries, and Product Tags.
- Each service class integrates with CQRS for command and query handling.
- Established mapping profiles for Product Galleries.

src/CMSMicroservice.Application/OrderVATCQ/Queries/GetOrderVAT/GetOrderVATQuery.cs

@@ -0,0 +1,11 @@
+using MediatR;
+
+namespace CMSMicroservice.Application.OrderVATCQ.Queries.GetOrderVAT;
+
+/// <summary>
+/// کوئری دریافت اطلاعات مالیات سفارش
+/// </summary>
+public class GetOrderVATQuery : IRequest<OrderVATDto?>
+{
+    public long OrderId { get; set; }
+}