feat:Make the XcmTransfer trait support transfer_multiasset_with_fee (#870)

Author: hqwangningbo

traits/src/xcm_transfer.rs

@@ -19,4 +19,13 @@ pub trait XcmTransfer<AccountId, Balance, CurrencyId> {
 		dest: MultiLocation,
 		dest_weight_limit: WeightLimit,
 	) -> DispatchResult;
+
+	/// Transfer `MultiAssetWithFee`
+	fn transfer_multiasset_with_fee(
+		who: AccountId,
+		asset: MultiAsset,
+		fee: MultiAsset,
+		dest: MultiLocation,
+		dest_weight_limit: WeightLimit,
+	) -> DispatchResult;
 }

xtokens/src/lib.rs

@@ -953,6 +953,17 @@ pub mod module {
 		) -> DispatchResult {
 			Self::do_transfer_multiasset(who, asset, dest, dest_weight_limit)
 		}
+
+		#[require_transactional]
+		fn transfer_multiasset_with_fee(
+			who: T::AccountId,
+			asset: MultiAsset,
+			fee: MultiAsset,
+			dest: MultiLocation,
+			dest_weight_limit: WeightLimit,
+		) -> DispatchResult {
+			Self::do_transfer_multiasset_with_fee(who, asset, fee, dest, dest_weight_limit)
+		}
 	}
 }