Requests the ready api on stream opening.

[scw00]

Description

We are developing a h3 connection pool which request a poll_ready api on stream opening. For example:

1. we retrieve all the queue of connection to find out a connection which is ready to open a stream
2. then pop that connection and propagate it to the h3 stack.

In this way, the task is pending on poll_ready if the connection can't open stream anymore and wake this task up until
next MAX_STREAMS incoming.

[djc]

It is unclear to me what you are asking. If it is a small concrete API proposal, I suggest you submit a PR instead.

[Ralith]

It sounds like you want to poll the stream accept futures. Is that not working for you?