Disable request body data rate limits per HTTP/2 stream

[JunTaoLuo]

Epic #8858

Currently we can disable the request body data rate limit for the entire server with

                    webBuilder.ConfigureKestrel(options =>
                    {
                        options.Limits.MinRequestBodyDataRate = null;
                    });

However, we want to be able to control this on a finer scale of per request/stream. We need this in since certain gRPC endpoints are client streaming methods which may not satisfy the request body data rate while all other endpoints of the app should still be subject to the request body data rate. Websocket scenarios will also benefit from this feature.

To implement this feature, it's likely we'll need to overhaul the accounting for request data rates. @halter73 has more context about the implementation here.

cc @Tratcher @davidfowl

[halter73]

There are two options we discussed:

1. A stopgap measure where we allow disabling rate limit for specific HTTP/2 streams/requests, but not modifying the rate limit to a non-null value.

2. A more thorough rearchitecture of HTTP/2 rate limiting which tracks and limits data rates at the stream level instead of the connection level. One potential wrinkle with this idea is that the default rate limit for an HTTP/2 connection would become 240 bytes/sec times the number of streams actively reading from the request body instead of just 240 bytes/sec if the app is actively reading from the request body like it is for HTTP/1.

[blowdart]

The stopgap seems a deeply undesirable idea.

[halter73]

@blowdart Why is that? It's basically what we do for WebSocket requests. If you have an endpoint where you know the client will use the request body to send intermittent messages, the stopgap measure gives you the behavior you want. Even the more thorough rearchitecture will allow you to get the behavior the stopgap solution give you. It just gives you more complete control.

[blowdart]

Because it's a half implementation? And more worrying if that feature is there then you known someone, somewhere is going to turn that on for normal requests.

[JamesNK]

@muratg @shirhatti Please prioritize this.