The getCookies method may need to be improved

When I found a minor problem with the getCookies method, I looked at the source code, on line 224 of **base.dart**,

`final split = cookie.split('=');`

If there is also '=' in the cookie value, the result of the split is not correct.

从 base.dart 第 224 行开始，使用值包含 '=' 的 cookie 跟踪 getCookies。确认当前的解析行为，并确定现有的 cookie 解析测试覆盖情况；当此类 cookie 的值能够正确返回且不影响普通 cookie 时，即视为完成。

由索引模型根据 Issue 内容生成。