auth: finer TSIG key deletion

[miodvallat]

Short description

This PR adds the ability to specifiy an algorithm, in addition to a name, when performing a TSIG key deletion.
For SQL backends, this relies upon an extra query.

Will fix #1466.

Note that, before this PR, the API would not let you have multiple TSIG keys with the same name, but different algorithms, while pdnsutil wouldn't mind. This restriction is lifted as part of these changes.

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]

Coverage Report for CI Build 32940036953

Coverage increased (+4.1%) to 71.232%

Details

• Coverage increased (+4.1%) from the base build.
• Patch coverage: 26 uncovered changes across 5 files (41 of 67 lines covered, 61.19%).
• 24 coverage regressions across 7 files.

Uncovered Changes

File	Changed	Covered	%
modules/remotebackend/remotebackend.cc	12	0	0.0%
modules/bindbackend/binddnssec.cc	8	2	25.0%
pdns/ws-auth.cc	18	14	77.78%
modules/remotebackend/httpconnector.cc	3	0	0.0%
pdns/dnsbackend.hh	1	0	0.0%
Total (12 files)	67	41	61.19%

Coverage Regressions

24 previously-covered lines in 7 files lost coverage.

File	Lines Losing Coverage	Coverage
pdns/recursordist/test-syncres_cc1.cc	5	80.2%
pdns/signingpipe.cc	5	83.68%
pdns/dnsdistdist/dnsdist-concurrent-connections.cc	4	90.13%
pdns/recursordist/test-syncres_cc2.cc	3	79.35%
pdns/tsigverifier.cc	3	77.22%
pdns/misc.cc	2	62.54%
pdns/ws-auth.cc	2	80.85%

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Coverage Stats

Relevant Lines:	173392
Covered Lines:	135392
Line Coverage:	78.08%
Relevant Branches:	82922
Covered Branches:	47186
Branch Coverage:	56.9%
Branches in Coverage %:	Yes
Coverage Strength:	6734587.31 hits per line

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💛 - Coveralls

[Habbie]

few notes. Shape looks right. Will finish review when the pdnsutil bug is fixed