[BHV-16348] Issue of co-existing Popup and contextual popup

Issue: If two different popups, both are extended from enyo.Popup exist
at the same time, it creates a conflict behavior as one popup doesn't
have information about the other's z-index.
Fix: The methods that removed that are overridden by moon. Popup and
moon.ContextualPopup
DCO-1.1-Signed-Off-By: Rajyavardhan P <rajyavardhan.p@lge.com>
Merge pull request #1741 from enyojs/BHV-16348.2-rajyavardhan.p

[BHV-16348] Issue of co-existing Popup and contextual popup

Reviewed-By: Derek Anderson (derek.anderson@lge.com)
Integrated-By: Ryan Duffy (ryan.duffy@lge.com)