update: the danak services module and add new route to fetch the danak service

src/modules/discounts/DTO/validate-discount.dto.ts

@@ -0,0 +1,11 @@
+import { IsNotEmpty, IsOptional, IsString } from "class-validator";
+
+export class ValidateDiscountDto {
+  @IsString()
+  @IsNotEmpty()
+  code: string;
+
+  @IsString()
+  @IsOptional()
+  productId?: string;
+}