Add custom error message for fork divergence in file editing

Gloria Odiporequested to merge
custom-error-message-in-files-updateservice into master

What does this MR do and why?

Adds custom error message for fork divergence in file editing

References

Add custom error message in files UpdateService (#569115)

Screenshots or screen recordings

BEFORE:

Screen_Recording_2025-12-06_at_02.19.44

AFTER:

Screen_Recording_2025-12-06_at_02.06.16

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Edited by Gloria Odipo

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