DM-55521: Allow regular mutable mappings for metadata failure annnotations.

[TallJimbo]

This is motivated by lsst.images types, which have a regular dict for their metadata instead of a PropertySet-like.

Checklist

• ran Jenkins
• ran and inspected package-docs build
• added a release note for user-visible changes to doc/changes

[codecov]

Codecov Report

❌ Patch coverage is 50.00000% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 88.87%. Comparing base (da2302b) to head (0b8186d).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
python/lsst/pipe/base/_status.py	50.00%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #574      +/-   ##
==========================================
- Coverage   88.95%   88.87%   -0.08%     
==========================================
  Files         161      161              
  Lines       22500    22504       +4     
  Branches     2673     2675       +2     
==========================================
- Hits        20014    20001      -13     
- Misses       1843     1853      +10     
- Partials      643      650       +7     

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