[OSS-components] Rework the solution from custom hasHtmlText assertion

[edouardmisset]

What does this PR do?

Removes the custom hasHtmlText assertion that was introduced in PR #652 and bumps qunit-dom to ^3.3.0 which ships a native hasHtml() method.

The custom assertion created a throwaway DOM element (document.createElement('div')) to parse HTML and compare text content — this approach "fakes reality" as flagged by Philippe. With qunit-dom 3.3+, we can use the built-in assert.dom(selector).hasHtml(expectedHtml) instead.

Related to: #DRA-4875

What are the observable changes?

• The custom assert.hasHtmlText() assertion is no longer available
• qunit-dom is upgraded from ^3.0.0 to ^3.3.0, making assert.dom(selector).hasHtml() available as a replacement

Good PR checklist

• Title makes sense
• Is against the correct branch
• Only addresses one issue
• Properly assigned
• Added/updated tests
• Added/updated documentation with Figma design link. Don't forget to replace "design" by "file" in the URL. For example https://www.figma.com/file/example
• Migrated touched components to Glimmer Components
• Properly labeled

[linear-code]

DRA-4875