Description

This PR updates serialization of the text-content of <style> elements, which should match the HTML spec.

Motivation and Context

• Escaping style content can cause the content to become invalid CSS

How Has This Been Tested?

• Unit tests

Types of changes

Fixes

• Updated xmlwriter to print style content as unescaped character data

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.