AWS, REST: Ability to pass request properties to the signer client

[adutra]

See this dev ML thread for context:

https://lists.apache.org/thread/gz5nm2xzlhzbc2y3sfossgflnkbm6vq5

[danielcweeks]

I think my biggest concern here is that we're trying to build a standard here that is still not covered by the spec. If there's specific information that we want to propagate (like namespace/table name/etc), we should probably formalize that though updating pathing and adding it to the REST spec.

This feels like a scenario like credentials where we started with properties that we ended up having to call out in the spec so that different implementations would have consistent behavior. While we might want to support properties, I don't think this is the answer to the original issue discussed.

[adutra]

@danielcweeks I agree with you, and in fact, my idea is to get this small change in and then, promote this new config property to the main spec along with s3.signer.uri and s3.signer.endpoint in #15112, where it would be properly documented at the spec level (none of these properties are documented currently). Wdyt?

Of course we can do the other way around and get #15112 in first, then add support for this in the main spec directly. But the changes here are so small that I feel it's not worth waiting.