BHV-18888 : DataGridList scroll to top and shows empty page when add mod...

...el to invisible list (priority 4)


## Issue
When moon.Panels is last parent and is hidden, moon.Panels.getAbsoluteShowing() return true
Thus, when moon.Panels and DataList inside Panels hide, DataList thinks that current showing status is true

## Fix
Refactor moon.Panels.getAbsoluteShowing() to call getAbsoluteShowing() of superkind

Enyo-DCO-1.1-Signed-off-by: SoonGil Choi (soongil.choi@lge.com)