Pass DnsRequestOptions to DNSSEC validating routines

[wiktor-k]

Hello,

This PR fixes the issue reported in #1735 and makes sure that the DnsRequestOptions that the client specifies are being forwarded to the DNSSEC validating functions.

The change is basically grabbing a copy of the options (because request is passed by value to send the original options cannot be used) and then adding the options parameter to validate_* functions and using that instead of DnsRequestOptions::default(). The additional parameter should not affect public API since all these functions are not marked pub.

When this PR gets merged I'll follow up with the "configurable max_request_depth" PR that doesn't make sense if the options are not being forwarded in the first place :).

Suggestions welcome! 👋

[djc]

This mostly looks good to me. It looks like a bunch of functions are taking a &DnsRequestOptions only to dereference it when using. If we're just going to dereference it anyway, why not take ownership? The mix between passing references and owned values seems confusing.

[wiktor-k]

Good idea, I'll fix that and re-submit. Thanks!

[wiktor-k]

I've adjusted the code. With your suggestions applied it looks cleaner. I couldn't avoid all explicit dereferences since options() returns a ref in DnsRequest but I don't think this is a big issue.

[wiktor-k]

Sorry for the noise @bluejekyll but what's the workflow for getting an approved PRs merged in here? I'm wondering if I can be of help in here...

[djc]

Hey, sorry for the slow feedback cycle here. I often like to get an additional review from @bluejekyll before a PR is merged, but he is currently on vacation. In the absence of his review, this is straightforward enough that I'll just merge it now.

[wiktor-k]

Ah, no worries. I asked because I've got yet another PR I planned to submit that depends on this one...

Thanks for the quick response and have a nice day! 👋