make successful payment use OrderInfo; derive Default on OrderInfo

src/types/order_info.rs

@@ -5,7 +5,7 @@ use crate::types::ShippingAddress;
 /// This object represents information about an order.
 ///
 /// [The official docs](https://core.telegram.org/bots/api#orderinfo).
-#[derive(Clone, Debug, Eq, Hash, PartialEq, Serialize, Deserialize)]
+#[derive(Clone, Debug, Eq, Hash, PartialEq, Serialize, Deserialize, Default)]
 pub struct OrderInfo {
     /// User's name.
     pub name: Option<String>,

src/types/pre_checkout_query.rs

@@ -35,5 +35,6 @@ pub struct PreCheckoutQuery {
     pub shipping_option_id: Option<String>,
 
     /// Order info provided by the user.
+    #[serde(default)]
     pub order_info: OrderInfo,
 }

src/types/successful_payment.rs

@@ -29,7 +29,8 @@ pub struct SuccessfulPayment {
     pub shipping_option_id: Option<String>,
 
     /// Order info provided by the user.
-    pub order_info: Option<OrderInfo>,
+    #[serde(default)]
+    pub order_info: OrderInfo,
 
     /// Telegram payment identifier.
     pub telegram_payment_charge_id: String,