Streams that have been received by the peer, but not accepted by the
user, can also receive a RST_STREAM. This is a legitimate pattern: one
could send a request and then shortly after, realize it is not needed,
sending a CANCEL.

However, since those streams are now "closed", they don't count towards
the max concurrent streams. So, they will sit in the accept queue, using
memory.

In most cases, the user is calling `accept` in a loop, and they can
accept requests that have been reset fast enough that this isn't an
issue in practice.

But if the peer is able to flood the network faster than the server
accept loop can run (simply accepting, not processing requests; that
tends to happen in a separate task), the memory could grow.

So, this introduces a maximum count for streams in the pending-accept
but remotely-reset state. If the maximum is reached, a GOAWAY frame with
the error code of ENHANCE_YOUR_CALM is sent, and the connection marks
itself as errored.

ref CVE-2023-26964
ref GHSA-f8vr-r385-rh5r

Closes hyperium/hyper#2877

The new option is available to both client and server `Builder`s.