chore: restore the ordering convention broken by the repr rebuild and alphabetize the remaining const blocks

[bdraco]

Summary

Seventeenth pass for #1835, from a fifth independent audit. #1880 inserted its methods at anchor positions rather than convention positions, silently breaking the stated ordering rule in DNSEntry, DNSRecord and DNSRRSet and drifting DNSRecord back toward the 2009 relative order; the rule is re applied (DNSRecord measures 0.70 shared name ordered LCS against the 2009 sequence, below the 0.78 the ordering round achieved). The timing and flag constant blocks in const.py, which had kept the 2009 non numeric sequence, are alphabetized under the same rule. Four docstrings the audit scored 0.65 to 0.86 against removed or corpus text are reworded (the section parser line, the three 16 bit writer lines) and the known answer suppression docstring now cites RFC 6762 section 7.1, whose rule its predicate implements.

Test plan

• full suite passes against a REQUIRE_CYTHON rebuild
• ordering re measured with the audit's stated metric

[github-actions]

Thanks for contributing! A quick note: this project is in the process of moving from LGPL-2.1 to Apache 2.0, see #1835.

By continuing with this pull request you agree that this new contribution is offered under Apache 2.0.

This notice does not affect your previous contributions. If you would like to consent to relicensing those as well, please post the consent statement on #1835; silence is never treated as consent for past work.

If offering this contribution under Apache 2.0 does not work for you, no hard feelings; reply with the exact phrase I do not agree to the Apache 2.0 license or simply close this pull request.

[codspeed-hq]

Merging this PR will not alter performance

✅ 24 untouched benchmarks

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_{Comparing fix_convention_and_const_order (85b6a80) with master (0e7c22a)}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.87%. Comparing base (0e7c22a) to head (85b6a80).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1886   +/-   ##
=======================================
  Coverage   99.87%   99.87%           
=======================================
  Files          33       33           
  Lines        3910     3910           
  Branches      568      568           
=======================================
  Hits         3905     3905           
  Misses          3        3           
  Partials        2        2           

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