This adds a middleware for overload protection that is intended to help protect against malicious scrapers.
It does this via [`codel`](https://github.com/bohde/codel), which will perform the following:
1. Limit the number of in-flight requests to some user-defined max
2. When in-flight requests have reached their begin queuing requests.
Logged-in requests having priority above logged-out requests
3. Once a request has been queued for too long,
it has a probabilistic chance to be rejected based on how overloaded the entire system is.
When a server experiences more traffic than it can handle,
this keeps latency low for logged-in users and rejects just
enough requests from logged-out users to not overload the service.
---------
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Giteabot <teabot@gitea.io>
c57304ac3f