Fix/preview track changes improvements

[usantos-at-wiris]

Description

This adds track changes suppor for mathml in source data and also adds a preview filtering for formulas

NOTE: the only file to review is plugin.js, utils.js, y parser.js

• Related Kanbanize Card: Link to KB-63220

Type of Change

Please delete options that are not relevant.

• [] Feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Chore (non-breaking change that doesn't add any functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update (changes to documentation only)
• Refactoring (non-breaking change that improves the code structure)

Checklist

• My code follows the style guidelines of this project ( Run yarn lint to check)
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (if applicable)
• My changes generate no new warnings or errors
• I have added tests that prove my fix is effective or that my feature works (if applicable)
• New and existing unit tests pass locally with my changes

How should be tested? (Manual or Automated Tests)

• Manual tests: I have tested this changes manually.

• Enter https://integrations.wiris.kitchen/feat/ck5-trackchanges-demo/html/ckeditor5/

• Enable Track changes clicking on the icon

• 

• Edit a formula

• 

• View the source, track changes should be visible in the source

<suggestion-start name="insertion:eb8a2f983a33d538a1740bc163a82e4ab:u1"></suggestion-start><math xmlns="http://www.w3.org/1998/Math/MathML"><msqrt><mn>47</mn><mo>-</mo><mi>x</mi></msqrt></math><suggestion-end name="insertion:eb8a2f983a33d538a1740bc163a82e4ab:u1"></suggestion-end><suggestion-start name="deletion:ebceb0d185ae1241817e98228482fced3:u1">

</suggestion-start><math xmlns="http://www.w3.org/1998/Math/MathML"><msqrt><mi>x</mi></msqrt></math><suggestion-end name="deletion:ebceb0d185ae1241817e98228482fced3:u1"></suggestion-end>

• Click on preview contents
• 
• Check that suggestions are applied on preview
• 

[carla-at-wiris]

Esto en la demo donde tendría que haber los cambios. Simplemente, he borrado el contenido que se ve directamente. En el source tampoco se ve:

[carla-at-wiris]

Como se puede ver, el preview funciona bien cuando hay sugerencias con imagenes y texto intercalado, pero se rompe el getData(), lo que rompe el source y lo que muchos users usan; la combiancion de editor.setData(editor.getData())
Screencast from 2026-01-21 14-51-43.webm

[carla-at-wiris]

[ncornaglia-at-wiris]

🚀

[carla-at-wiris]

Queda aprobada a sabiendas de que tenemos que contactar con el equipo de CK para gestionar el error que aparece a continuación:

• Cuando tenemos una fórmula al final modificada con el track changes
• Hacemos algunas otras modificaciones sencillas en el contenido del editor
• Validamos el source
• Hacemos un editor set Data de editor getData
• Borramos todo el contenido del editor
• Le damos a preview y se rompe como en la imagen