[BHV-14587]MoonPopup controls are not focusable when there is an active ...

...scroller below it

The commit is to provide translation to Poup in  Z-direction, so that It
won't interfere with the controls below it.
Enyo-DCO-1.1-Signed-off-by: Rajyavardhan P rajyavardhan.p@lge.com
Additionally, we might consider storing the value of `translateZ` as a private property that we can use in our transform object so we have this value in only one location and can easily change it as necessary.