Support for timeout propagation in async requests

[dxxyy]

Give the possibility to clients to specify a timeout while performing async requests.
More details in #616

[scottf]

Looks good. Need to make sure the commit is verified.

[scottf]

@dxxyy This PR is conditionally approved. If you want to be kept as the contributor, you must verify your commit. Here is a doc to get you started: https://docs.github.com/en/authentication/managing-commit-signature-verification

[dxxyy]

@dxxyy This PR is conditionally approved. If you want to be kept as the contributor, you must verify your commit. Here is a doc to get you started: https://docs.github.com/en/authentication/managing-commit-signature-verification

Thanks! Commit now verified.

[scottf]

@dxxyy I don't see it verified. If you are setup for verification, it's probably easiest to rebase/remove all your commits and start over with a new PR.

[dxxyy]

I did indeed the rebase and the merge commit lost the verification. I will close this and create a new one from scratch. Thanks