refactor(domain): 更新汇率接口并添加 UID 参数

- 在 ExchangeRepoInterface 中添加了 uid 参数
- 在 ProductRepo 中实现了 getRate 方法，增加了 uid 参数
- 更新了单元测试，添加了 uid 参数

tests/Feature/Product/QueryPointRateTest.php

@@ -19,6 +19,8 @@ it('can query point rate', function () {
     $from = PointType::FtaiAligner;
     $to = PointType::LuxPoint;
 
-    $rate = $repo->getRate($from, $to);
+    $uid = 'cn3321';
+
+    $rate = $repo->getRate($from, $to, $uid);
     expect($rate)->toBeFloat();
 });