ECOM-7571 Add handlingFee field to items info

`handlingFee` contains breakdown of only handling fee for the item same as `shipping` contains breakdown of only shipping cost

Author: OlegShtchLS

src/main/kotlin/com/ecwid/apiclient/v3/converter/FetchedOrder.kt

@@ -145,6 +145,7 @@ fun FetchedOrder.OrderItem.toUpdated(): UpdatedOrder.OrderItem {
 		price = price,
 		productPrice = productPrice,
 		shipping = shipping,
+		handlingFee = handlingFee,
 		tax = tax,
 		fixedShippingRate = fixedShippingRate,
 		couponAmount = couponAmount,

src/main/kotlin/com/ecwid/apiclient/v3/dto/cart/request/OrderForCalculate.kt

@@ -85,6 +85,7 @@ data class OrderForCalculate(
 		val isCustomerSetPrice: Boolean? = null,
 		val selectedPrice: SelectedPrice? = null,
 		val shipping: Double? = null,
+		val handlingFee: Double? = null,
 		val tax: Double? = null,
 		val fixedShippingRate: Double? = null,
 		val couponAmount: Double? = null,

src/main/kotlin/com/ecwid/apiclient/v3/dto/cart/result/CalculateOrderDetailsResult.kt

@@ -140,6 +140,7 @@ data class CalculateOrderDetailsResult(
 		val priceWithoutTax: Double? = null,
 		val productPrice: Double? = null,
 		val shipping: Double? = null,
+		val handlingFee: Double? = null,
 		val tax: Double? = null,
 		val fixedShippingRate: Double? = null,
 		val couponAmount: Double? = null,

src/main/kotlin/com/ecwid/apiclient/v3/dto/cart/result/FetchedCart.kt

@@ -132,6 +132,7 @@ data class FetchedCart(
 		val price: Double? = null,
 		val productPrice: Double? = null,
 		val shipping: Double? = null,
+		val handlingFee: Double? = null,
 		val tax: Double? = null,
 		val fixedShippingRate: Double? = null,
 		val couponAmount: Double? = null,

src/main/kotlin/com/ecwid/apiclient/v3/dto/order/request/UpdatedOrder.kt

@@ -153,6 +153,7 @@ data class UpdatedOrder(
 		val isCustomerSetPrice: Boolean? = null,
 		val selectedPrice: SelectedPrice? = null,
 		val shipping: Double? = null,
+		val handlingFee: Double? = null,
 		val tax: Double? = null,
 		val taxable: Boolean? = null,
 		val fixedShippingRate: Double? = null,

src/main/kotlin/com/ecwid/apiclient/v3/dto/order/result/FetchedOrder.kt

@@ -183,6 +183,7 @@ data class FetchedOrder(
 		val selectedPrice: SelectedPrice? = null,
 		val priceWithoutTax: Double? = null,
 		val shipping: Double? = null,
+		val handlingFee: Double? = null,
 		val tax: Double? = null,
 		val fixedShippingRate: Double? = null,
 		val couponAmount: Double? = null,

src/main/kotlin/com/ecwid/apiclient/v3/dto/subscriptions/result/FetchedSubscription.kt

@@ -107,6 +107,7 @@ data class FetchedSubscription(
 		val price: Double? = null,
 		val productPrice: Double? = null,
 		val shipping: Double? = null,
+		val handlingFee: Double? = null,
 		val tax: Double? = null,
 		val fixedShippingRate: Double? = null,
 

src/test/kotlin/com/ecwid/apiclient/v3/entity/CartsTest.kt

@@ -11,6 +11,7 @@ import com.ecwid.apiclient.v3.dto.order.request.UpdatedOrder
 import com.ecwid.apiclient.v3.util.*
 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Assertions.assertNotNull
+import org.junit.jupiter.api.Assertions.assertNull
 import org.junit.jupiter.api.BeforeEach
 import org.junit.jupiter.api.Disabled
 import org.junit.jupiter.api.Test
@@ -86,6 +87,7 @@ class CartsTest : BaseEntityTest() {
 			assertEquals(orderItem.price, cartItem.price)
 			assertEquals(orderItem.productPrice, cartItem.productPrice)
 			assertEquals(orderItem.shipping, cartItem.shipping)
+			assertEquals(orderItem.handlingFee, cartItem.handlingFee)
 			assertEquals(orderItem.tax, cartItem.tax)
 			assertEquals(orderItem.fixedShippingRate, cartItem.fixedShippingRate)
 			assertEquals(orderItem.couponAmount, cartItem.couponAmount)
@@ -296,6 +298,7 @@ class CartsTest : BaseEntityTest() {
 			assertEquals(forCalculateItem.price, calculatedItem.price)
 			assertEquals(forCalculateItem.productPrice, calculatedItem.productPrice)
 			assertEquals(0.0, calculatedItem.shipping)
+			assertNull(calculatedItem.handlingFee)
 			assertEquals(forCalculateItem.fixedShippingRate, calculatedItem.fixedShippingRate)
 			assertEquals(
 				null,
@@ -480,6 +483,7 @@ class CartsTest : BaseEntityTest() {
 			price = 22.2,
 			productPrice = 33.3,
 			shipping = 44.4,
+			handlingFee = 77.7,
 			tax = 55.5,
 			fixedShippingRate = 66.6,
 			couponAmount = 15.0,

src/test/kotlin/com/ecwid/apiclient/v3/rule/nullablepropertyrules/CalculateOrderDetailsResultRules.kt

@@ -60,6 +60,7 @@ val calculateOrderDetailsResultNullablePropertyRules: List<NullablePropertyRule<
 	IgnoreNullable(CalculateOrderDetailsResult.OrderItem::selectedOptions),
 	AllowNullable(CalculateOrderDetailsResult.OrderItem::combinationId),
 	IgnoreNullable(CalculateOrderDetailsResult.OrderItem::shipping),
+	AllowNullable(CalculateOrderDetailsResult.OrderItem::handlingFee),
 	IgnoreNullable(CalculateOrderDetailsResult.OrderItem::shortDescription),
 	IgnoreNullable(CalculateOrderDetailsResult.OrderItem::sku),
 	IgnoreNullable(CalculateOrderDetailsResult.OrderItem::tax),

src/test/kotlin/com/ecwid/apiclient/v3/rule/nullablepropertyrules/FetchedCartRules.kt

@@ -107,6 +107,7 @@ val fetchedCartNullablePropertyRules: List<NullablePropertyRule<*, *>> = listOf(
 	IgnoreNullable(FetchedCart.OrderItem::selectedOptions),
 	AllowNullable(FetchedCart.OrderItem::combinationId),
 	IgnoreNullable(FetchedCart.OrderItem::shipping),
+	AllowNullable(FetchedCart.OrderItem::handlingFee),
 	IgnoreNullable(FetchedCart.OrderItem::shortDescription),
 	IgnoreNullable(FetchedCart.OrderItem::sku),
 	IgnoreNullable(FetchedCart.OrderItem::tax),