Add deep dropping of nulls when checking field equality

[tumbledwyer]

Description

Addresses with null values in streetLevelDetails were incorrectly being picked up as changed when they are effectively the same value.

Fixes: #11122 (comment)

Checklist

• I have linked the correct Github issue under "Development"
• I have tested the changes locally, and written appropriate tests
• I have tested beyond the happy path (e.g. edge cases, failure paths)
• I have updated the changelog with this change (if applicable)
• I have updated the GitHub issue status accordingly

[github-actions]

Oops! Looks like you forgot to update the changelog. When updating CHANGELOG.md, please consider the following:

• Changelog is read by country implementors who might not always be familiar with all technical details of OpenCRVS. Keep language high-level, user friendly and avoid technical references to internals.
• Answer "What's new?", "Why was the change made?" and "Why should I care?" for each change.
• If it's a breaking change, include a migration guide answering "What do I need to do to upgrade?".

[github-actions]

ℹ️ Coverage metrics explained:
• Statements — Executed code statements (basic logic lines)
• Branches — Tested decision paths (if/else, switch, ternaries)
• Functions — Functions invoked during tests
• Lines — Source lines executed

[github-actions]

📊 commons test coverage

Statements: 67.18%
Branches:   33.23%
Functions:  50.25%
Lines:      66.59%
Updated at: Fri, 09 Jan 2026 07:49:09 GMT

[github-actions]

📊 events test coverage

Statements: 85.02%
Branches:   83.99%
Functions:  90.47%
Lines:      85.02%
Updated at: Fri, 09 Jan 2026 07:53:58 GMT

[ocrvs-bot]

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