Cache 204 - No content

## 💬 Questions and Help

If I understand the code correctly currently only 200 and 202 status codes are added to the cache.

https://github.com/Baseflow/flutter_cache_manager/blob/c7881776325441f3900277499615981c40d12284/flutter_cache_manager/lib/src/web/web_helper.dart#L23-L24

In my case I have a image API endpoint which *tries* to generate a image/logo/etc. based on a user-provided website URL. Since the user input could just as well be an internal URL or just broken, it is perfectly fine for the endpoint to return a 404 response. Right now this is not cached on the client side but requested every time.

Is this the intended behavior, or any way to cache non-existent URLs?

阅读链接行中的 lib/src/web/web_helper.dart，以确认当前缓存了哪些 HTTP 状态码。明确所请求的行为是否涵盖 204、404 或其他非成功响应，然后验证所选行为能够防止针对报告的 image API 情况重复发出请求。

由索引模型根据 Issue 内容生成。