elementary widget: Do super's efl_gfx_color_set to apply color to widget itself

elementary widget: Do super's efl_gfx_color_set to apply color to widget itself

Summary:
The efl_gfx_color interface was not applied properly.
The implementation code of evas_object_smart_color_set was moved
to efl_gfx_color_set implementation code. But, these two functions are not same.
In efl_gfx_color_set impl, it has to call super's color set to apply
the given color values to widget object itself.

This bug caused color_set/get test failure and the following bug.
1. elm_image_add
2. evas_object_color_set
3. elm_image_file_set
4. show. See the given color is not applied. It was applied in the past.

Test Plan: color_set/get to elm_image object is included in test suite.

Reviewers: raster, cedric, herdsman, woohyun

Reviewed By: cedric

Subscribers: #committers, zmike

Tags: #efl

Differential Revision: https://phab.enlightenment.org/D6163

Reviewed-by: Cedric BAIL <cedric@osg.samsung.com>