auth: simple protobuf logging support

[miodvallat]

Short description

This is intended to supersede #16073 while @Habbie is unfortunately too short on time to work on it. It is rebased and the remote logger code has been modified to work with auth and structured logging.

Checklist

I have:

• read the CONTRIBUTING.md document
• read and accepted the Developer Certificate of Origin document, including the AI Policy, and added a "Signed-off-by" to my commits
• 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 23435603457

Details

• 17 of 52 (32.69%) changed or added relevant lines in 2 files are covered.
• 38 unchanged lines in 10 files lost coverage.
• Overall coverage decreased (-0.01%) to 70.966%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pdns/auth-main.cc	6	8	75.0%
pdns/packethandler.cc	11	44	25.0%

Files with Coverage Reduction	New Missed Lines	%
modules/gpgsqlbackend/gpgsqlbackend.cc	1	84.78%
pdns/misc.cc	2	61.45%
pdns/recursordist/aggressive_nsec.cc	2	65.8%
pdns/sstuff.hh	2	59.34%
pdns/iputils.hh	3	75.39%
pdns/stubresolver.cc	3	74.86%
pdns/auth-secondarycommunicator.cc	4	59.94%
pdns/recursordist/rec-taskqueue.cc	4	40.34%
pdns/packethandler.cc	5	69.03%
pdns/dnsdistdist/dnsdist-tcp.cc	12	74.45%

Totals
Change from base Build 23435036786:	-0.01%
Covered Lines:	130931
Relevant Lines:	168404

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💛 - Coveralls