docs: Update efl_object lifecycle docs
Summary:
Explained the different phases, added method refs and removed outdated links.
Ref T7557
Reviewers: zmike, bu5hm4n
Reviewed By: bu5hm4n
Subscribers: cedric, reviewers, committers
Tags: efl
Maniphest Tasks: T7557
Differential Revision: https://phab.enlightenment.org/D7903