[BHV-14150]PopupSample: Moonstone Popup closes abnormally on spotlight events

Issue: To prevent 5-way behavior, when popup is open, spotlightfocus
events are captured and handled in popup.js. As spotlight implementation
is changed some code change is required.
Fix: Code is updated in accordance with the new spotlight behavior.
Enyo-DCO-1.1-Signed-off-by: Rajyavardhan P rajyavardhan.p@lge.com
Merge pull request #1612 from enyojs/BHV-14150-rajyavardhan.p

[BHV-14150]PopupSample: Moonstone Popup closes abnormally on spotlight e...