DM-49446: Improvements to diff tool

[JeremyMcCormick]

This PR is a major overhaul of the diff module to fix issues/bugs in the comparison tools, add a few new features, and restructure the formatted diff output into JSON instead of unstructured text. The associated Jira ticket contains more complete information on what was done.

The module was rewritten to be much simpler, leveraging the internal data structures of deepdiff more than previously to avoid excessive data manipulations and transformations.

NOTE: The database diff tool, which is modified on this PR, mainly with improved error handling, is planned to be moved to another module entirely with its own, dedicated command (DM-51697). The structure of its implementation reflected in this PR will be heavily revised, based on that work.

Checklist

• Ran Jenkins
• Added a release note for user-visible changes to docs/changes

[codecov]

Codecov Report

Attention: Patch coverage is 89.43894% with 32 lines in your changes missing coverage. Please review.

Project coverage is 92.36%. Comparing base (fbddf40) to head (960d026).

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
python/felis/diff.py	77.14%	31 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #138      +/-   ##
==========================================
- Coverage   92.76%   92.36%   -0.41%     
==========================================
  Files          22       22              
  Lines        2918     2998      +80     
  Branches      305      306       +1     
==========================================
+ Hits         2707     2769      +62     
- Misses        132      156      +24     
+ Partials       79       73       -6     

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