efl_ui/layout_base: add "finger_size_multiplier" property

efl_ui/layout_base: add "finger_size_multiplier" property

Summary:
this feature is set on objects which inherit from layout_base in order to
allow automatically application of variable finger sizes based on a
widget's needs

an example of this would be a calendar, which is 7:8 fingers

this functionality is disabled by passing 0,0 as the property

@feature

Depends on D9436

Reviewers: bu5hm4n

Reviewed By: bu5hm4n

Subscribers: segfaultxavi, cedric, #reviewers, #committers

Tags: #efl_widgets

Maniphest Tasks: T8059

Differential Revision: https://phab.enlightenment.org/D9437