rec: allow overriding remote address from preoutquery()

[elenril]

Short description

The LUA preoutquery() hook can now modify dq.remoteaddr to override the remote server to query.

Fixes #6798

Checklist

I have:

• read the CONTRIBUTING.md document
• compiled this code
• tested this code
• included documentation (including possible behaviour changes)
• documented the code
• added or modified regression test(s)
• added or modified unit test(s)

[coveralls]

Pull Request Test Coverage Report for Build 17795654203

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 7 of 7 (100.0%) changed or added relevant lines in 2 files are covered.
• 18 unchanged lines in 6 files lost coverage.
• Overall coverage increased (+0.03%) to 66.037%

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Files with Coverage Reduction	New Missed Lines	%
pdns/recursordist/syncres.cc	1	81.25%
modules/godbcbackend/sodbc.cc	2	70.13%
pdns/recursordist/rec-main.cc	2	64.68%
pdns/rcpgenerator.cc	3	90.56%
pdns/dnsdistdist/dnsdist-lbpolicies.cc	4	72.36%
pdns/recursordist/pdns_recursor.cc	6	73.64%

Totals
Change from base Build 17789672259:	0.03%
Covered Lines:	128910
Relevant Lines:	166497

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💛 - Coveralls

[omoerbeek]

Please have some patience. We are certainly considering this, but first we need to finish the 5.3.0 release.

[elenril]

Please have some patience. We are certainly considering this, but first we need to finish the 5.3.0 release.

No problem, I did expect to wait until the release, and I've been on vacation anyway.

[omoerbeek]

I rebased the code and added a fix for when the new remote is TCP and port 853, it should switch to DoT if needed.
This PR will need a test.

[omoerbeek]

As I suspected, there's an issue with the nsspeed bookkeeping: the original IP stays in the table at 0ms, while the updated IP gets an entry > 0ms. The speed based selection mechanism then keeps selecting the fast 0ms entry, which is never updated, basically breaking the mechanism that selects the fastest nameserver.