modules/hints: NODATA answers also for non-address queries

Apparently the original implementation in 14de9110 didn't think of this. Noticed by Fantomas: https://forum.turris.cz/t/kresd-returns-nxdomain-for-local-mx-records/12991

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As a part of #535 we'll most likely scrap the whole module, but that won't really happen so soon, and the fix is quite easy.

added bug easyfix minor labels

Please add a test. It is larger change than I'm comfortable merging without automated test... Luckily we can we-use it later for new implementation!

added 4 commits

• 0ffcc8f2 - tests: move check_answer() into require('tests_utils')
• de2b9535 - tests check_answer(): do not return until finished
• a84dcf00 - tests check_answer(): support testing NODATA
• 4a216aa9 - modules/hints/tests: test NODATA, fix module order

Compare with previous version

Right, I didn't realize that. Maybe the way to configure hints will change in time, but it should be trivial to amend the test when that happens.

Another instance of test being much harder to write than code itself. (Not trying to say they're not useful.)

added 7 commits

• 4a216aa9...6552d471 - 2 commits from branch master
• 88df6d27 - modules/hints: NODATA answers also for non-address queries
• 876bea09 - tests: move check_answer() into require('tests_utils')
• 5d128baa - tests check_answer(): do not return until finished
• 491777e9 - tests check_answer(): support testing NODATA
• db4aad94 - modules/hints/tests: test NODATA, fix module order

Compare with previous version

One TODO is left in the test, but I hope I can avoid it "for now".

merged

mentioned in commit 6c98b011