edje: Edje_Edit - add edje_edit_group_orientation_set/_get.

edje: Edje_Edit - add edje_edit_group_orientation_set/_get.

Summary:
Set or get orientation for group:
0 for EDJE_ORIENTATION_AUTO, 1 for EDJE_ORIENTATION_LTR, 2 for EDJE_ORIENTATION_RTL.
_get return 0 (AUTO), 1 (LTR), 2(RTL) orientation was setted for the group. -1 if an error occurred.
_set return EINA_TRUE if successful, EINA_FALSE otherwise.

@feature

Reviewers: cedric, raster, seoz, Hermet

CC: reutskiy.v.v, cedric
Differential Revision: https://phab.enlightenment.org/D938

Signed-off-by: Cedric BAIL <c.bail@partner.samsung.com>