auth API: when querying with rrset_name, respect it for comments too

[Habbie]

Short description

While rrset_name (plus optionally rrset_type) turns list into lookup for records, we don't have lookup for comments, so we need to filter those comments out explicitly after listing them all from the database.

This also shows that in case of a zone with lots of comments, the 'rrset filter' (which actually -is- efficient for records) does a lot of extra work for comments.

Needs a test.

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)
• checked that this code was merged to master

[coveralls]

Pull Request Test Coverage Report for Build 8572835073

Details

• 0 of 31 (0.0%) changed or added relevant lines in 1 file are covered.
• 2868 unchanged lines in 44 files lost coverage.
• Overall coverage decreased (-1.6%) to 57.917%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pdns/ws-auth.cc	0	31	0.0%

Files with Coverage Reduction	New Missed Lines	%
pdns/base64.cc	1	82.09%
ext/yahttp/yahttp/cookie.hpp	1	2.7%
modules/bindbackend/binddnssec.cc	1	56.73%
pdns/pollmplexer.cc	1	82.39%
ext/yahttp/yahttp/reqresp.cpp	1	47.34%
pdns/comment.hh	1	0.0%
pdns/opensslsigners.cc	2	60.93%
pdns/auth-primarycommunicator.cc	2	54.16%
pdns/tcpiohandler.cc	2	66.67%
ext/yahttp/yahttp/router.hpp	2	21.43%

Totals
Change from base Build 8569311617:	-1.6%
Covered Lines:	111211
Relevant Lines:	159269

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💛 - Coveralls