efl_ui_focus_manager_root_focus: ensure that adapter is part of viewport

efl_ui_focus_manager_root_focus: ensure that adapter is part of viewport

This ensures that the adapter part is part of the viewport elements and
border elements. This is done in order to support cases where a
elm_scroller content is not focusable. Before the element was not
correctly in viewport, and so not correctly registered.

ref T6804

Differential Revision: https://phab.enlightenment.org/D7364