feat(gitops-engine): show and format detailed field changes in StatefulSet immutable field errors

[aali309]

Fixes: #21209
Part of: #21209
Replaces: argoproj/gitops-engine#654

This PR Improves error messages when attempting to modify immutable fields in StatefulSets by showing exactly which fields changed and their before/after values.

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this does not need to be in the release notes.
• The title of the PR states what changed and the related issues number (used for the release note).
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Before the change:

After the change:

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 62.25%. Comparing base (791e924) to head (a27602c).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #25171      +/-   ##
==========================================
- Coverage   62.32%   62.25%   -0.08%     
==========================================
  Files         351      351              
  Lines       49330    49330              
==========================================
- Hits        30746    30711      -35     
- Misses      15656    15684      +28     
- Partials     2928     2935       +7     

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