evas/gl : Do not re-preload image data if texture is successfully uploaded with image...

evas/gl : Do not re-preload image data if texture is successfully uploaded with image data.

Summary:
'cached' flag is not enough to check whethere data is loaded and texture is uploaded.
so check more options for prevent re-preload image data on gl-backend.

Test Plan: Local Test (elementary_test : elm images)

Reviewers: jpeg, eunue

Reviewed By: jpeg

Subscribers: cedric, jiin.moon, wonsik, spacegrapher

Differential Revision: https://phab.enlightenment.org/D3446

Change-Id: Ia15c6ec4a22a6b48921baab5d00992bc0918c477
Origin: upstream