Residual stream

In some case while just using the provided `Connection` method it is possible to have residual stream that are never collected/cleaned within a quiche Connection.

Here is how to trigger it with a code sample
```rust
let mut pipe = testing::Pipe::with_server_config(&mut config).unwrap();

pipe.handshake().unwrap();

let mut buf = [0u8;32];

// Open a stream and send some data
assert_eq!(pipe.client.stream_send(2, b"hello world", false), Ok(11));
pipe.advance().unwrap();

// Send a reset_stream frame
pipe.client.stream_shutdown(2, Shutdown::Write, 0).unwrap();
pipe.advance().unwrap();

// check that the stream are correctly handled
assert_eq!(pipe.client.streams.len(), 0);
assert_eq!(pipe.server.streams.len(), 1);

// Shutdown on the server side
pipe.server.stream_shutdown(2, Shutdown::Read, 0).unwrap();

// Now to be coherent we should have no more stream in the server side but this assertion is true
eprintln!("this assertion should failed");
assert_eq!(pipe.server.streams.len(), 1); // we expect the length to be 0 here

// But in fact the stream is not collected and quiche behave as follows
assert_eq!(pipe.server.stream_readable_next(), None);
assert_eq!(pipe.server.stream_recv(2, &mut buf), Err(Error::Done));
assert_eq!(pipe.server.streams.len(), 1);

// It is now impossible to collect/cleanup the stream
```

I can make a pull request to fix this if you are interested
Best regards.