WIP: Use WebComponents v2 for gl-emoji element

What does this MR do?

Replaces deprecated document.registerElement (WebComponents v1) which is only supported by Chrome and Opera without polyfill with window.customElements.define (WebComponents v2) which is supported by Firefox and Safari as well. Polyfill for other Browsers is provided.

What are the relevant issue numbers?

Closes #51853 (closed)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.