efl_ui_textbox / efl_ui_image_zoomable: remove duplicated code

Summary:
these implementations were totally equal to what is there in
efl_ui_layout. No point in keeping them. (Note, entry_edje is equal to
resize_obj)

ref T8522

Reviewers: segfaultxavi, cedric, zmike, woohyun

Subscribers: reviewers, committers

Tags: efl

Maniphest Tasks: T8522

Differential Revision: https://phab.enlightenment.org/D11141