Fix/parse viewer namespaced mathml

[jguillen-at-wiris]

Description

Problem

The MathType viewer only detected standard elements, missing namespaced variants like <m:math> and mml:math commonly found in XML Documents.

Solution

Enhanced the MathML selector in the renderMathML function to detect multiple MathML element formats:

• Standard elements
• Properly namespaced elements using getElementsByTagNameNS("*", "math")
• Namespaced elements with literal colons using CSS selectors (m:math, mml:math)

This ensures mathematical formulas are rendered regardless of the namespace prefix used, improving compatibility with various document sources without breaking existing functionality.

• Related Kanbanize Card: NONE
• Related GitHub Issue: NONE

Type of Change

• Feature (non-breaking change which adds functionality)

Checklist

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

How should be tested? (Manual or Automated Tests)

• Manual tests:
• The demo in this repository works as expected.
• I have tested this changes manually by checking an Arbortext generated DITA XML file renders MathML properly in this demo.

Feel free to consider adding that demo to the current viewer demo in this repository.