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Explained the different phases, added method refs and removed outdated links.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