ds: add order definition

src/libtrader/ds/account/order.rs

@@ -0,0 +1,11 @@
+use crate::ds::account::position::PositionType;
+
+#[derive(PartialEq, Debug)]
+pub struct Order {
+    pub action_type: PositionType,
+    pub stock_symbol: String,
+    pub stock_price: i64,
+    pub stock_amount: i64,
+    pub stock_filled: i64,
+    pub is_filled: bool,
+}