Revert "Replace several internal protobufs with Go structs (#3878)"

[JAORMX]

Summary

This reverts commit 40cbccd.

This PR breaks the smoke tests. Explicitly the homoglyph and vulncheck
tests.

Fixes #(related issue)

Change Type

Mark the type of change your PR introduces:

• Bug fix (resolves an issue without affecting existing features)
• Feature (adds new functionality without breaking changes)
• Breaking change (may impact existing functionalities or require documentation updates)
• Documentation (updates or additions to documentation)
• Refactoring or test improvements (no bug fixes or new functionality)

Testing

Review Checklist:

• Reviewed my own code for quality and clarity.
• Added comments to complex or tricky code sections.
• Updated any affected documentation.
• Included tests that validate the fix or feature.
• Checked that related changes are merged.

[coveralls]

coverage: 52.773% (+0.03%) from 52.747%
when pulling 9175b5c on revert-3878
into f1fba17 on main.