Gengrid: Focus highlight should move to nearest visible object.
Gengrid: Focus highlight should move to nearest visible object.

Summary:
If item_loop is not enabled, the focus highlight should move to nearest visible object
with key events.

Test Plan: elementary_test -to "gengrid 2"

Reviewers: seoz, raster

Subscribers: sachin.dev, seoz

Differential Revision: https://phab.enlightenment.org/D1261

FlorentRevest/Elementary,rvandegrift/elementary,rvandegrift/elementary,FlorentRevest/Elementary,tasn/elementary,tasn/elementary,rvandegrift/elementary,tasn/elementary,rvandegrift/elementary,tasn/elementary,FlorentRevest/Elementary,tasn/elementary,FlorentRevest/Elementary