efl_ui: move clickable from efl to efl_ui
Summary:
efl_ui_clickable is now a mixin. The mixin now brings two APIs the press
and unpress API can be used to tell the implementation the state of the
presses. Within the implementation the calls to press / unpress are then
converted to longpress / clicked events.
Reviewers: zmike, segfaultxavi, cedric
Reviewed By: zmike
Subscribers: reviewers, committers
Tags: efl
Differential Revision: https://phab.enlightenment.org/D8820