BHV-11367: Support marquee function with HighlightText

## Problem
When using HighlightText with marqueeItem, marquee text is not created within marqueeItem.
- The renderDelegate (HighlightTextDelegate) is not checking the children and this makes this.render() in _marquee_createMarquee not actually create marqueeText.
- The marqueeItem is rendering marqueeText content with default renderDelegate. But highlighed text should be rendered with renderDelegate.

## Fix
- Adding highlight text with marquee case in Sample
- Let marqueeText know the highlightText renderDelegate so it can render highlighted text inside of marquee.
- Adding highlightText renderDelegate function to consider multiple children case.

DCO-1.1-Signed-Off-By: Kunmyon Choi kunmyon.choi@lge.com
highlightText is global variable? I can not find the local declaration