Summary:
https://phab.enlightenment.org/T5900
Creating base class(efl_ui_spin) to support various shape of spinner.
Added button interaction widget efl_ui_spin_button inherited from efl_ui_spin.
Test Plan: Add tests in elementary_test.
Reviewers: Jaehyun_Cho, woohyun, jpeg, singh.amitesh
Subscribers: jenkins, id213sin, cedric, jpeg
Differential Revision: https://phab.enlightenment.org/D5424
