BHV-12790: Dynamic content change on HighlightText is not work when used with marquee

### Issue
If marquee is used with highlight text, highlight text can have marqueeText as a child.
In generateInnerHtml, marqueeText doesn't have search and highlightClasses property on it.
So, it goes to usual content change routine.

### Fix
Pass search and highlightClasses properties to child controls(marqueeText).
Adding empty content check for safety.
Adding test case on sample.

DCO-1.1-Signed-Off-By: Kunmyon Choi kunmyon.choi@lge.com