efl_ui/layout: implement group_calc, add finger size for inherited layouts

efl_ui/layout: implement group_calc, add finger size for inherited layouts

Summary:
this adds a group_calc implementation for the layout object (not layout_base)
to allow differentiation between inherited layout calcs and layout object
calcs

by using this, we can automatically apply finger size to inherited layout
calcs if the implementation ever reaches this point

Depends on D9435

Reviewers: bu5hm4n

Reviewed By: bu5hm4n

Subscribers: bu5hm4n, cedric, #reviewers, #committers

Tags: #efl_widgets

Maniphest Tasks: T8059

Differential Revision: https://phab.enlightenment.org/D9436