Summary: remove the elm legacy name of efl ui theme
Test Plan: run elementary_test and test efl ui widget cases
Reviewers: Jaehyun_Cho, woohyun, cedric, raster, jpeg
Reviewed By: Jaehyun_Cho
Differential Revision: https://phab.enlightenment.org/D5934
Efl.Ui.Pager is a widget which contains many pages in a linear fashion
and allows users to scroll through them.
Users can attach Efl.Page.Transition and Efl.Page.Indicator to a pager.