Add more tests for includePanelProcessor.ts

[AgentHagu]

What is the purpose of this pull request?

• Documentation update
• Bug fix
• Feature addition or enhancement
• Code maintenance
• DevOps
• Improve developer experience
• Others, please explain:

Overview of changes:
Adds more tests to includePanelProcessor.test.ts.

Adds assertions to check the errors logged by logger using jest.spyOn

Anything you'd like to highlight/discuss:
These changes are derived from the PR #2639

Testing instructions:

Proposed commit message: (wrap lines at 72 characters)
Add more tests for includePanelProcessor.ts

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Checklist: ☑️

• Updated the documentation for feature additions and enhancements
• Added tests for bug fixes or features
• Linked all related issues
• No unrelated changes

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Reviewer checklist:

Indicate the SEMVER impact of the PR:

• Major (when you make incompatible API changes)
• Minor (when you add functionality in a backward compatible manner)
• Patch (when you make backward compatible bug fixes)

At the end of the review, please label the PR with the appropriate label: r.Major, r.Minor, r.Patch.

Breaking change release note preparation (if applicable):

• To be included in the release note for any feature that is made obsolete/breaking

Give a brief explanation note about:

• what was the old feature that was made obsolete
• any replacement feature (if any), and
• how the author should modify his website to migrate from the old feature to the replacement feature (if possible).

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 53.60%. Comparing base (8e52d96) to head (48624de).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2704      +/-   ##
==========================================
+ Coverage   52.84%   53.60%   +0.75%     
==========================================
  Files         130      130              
  Lines        7162     7162              
  Branches     1572     1498      -74     
==========================================
+ Hits         3785     3839      +54     
+ Misses       3222     3026     -196     
- Partials      155      297     +142     

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