edje: fix edje RTL description in case of custom state of a part

edje: fix edje RTL description in case of custom state of a part
This patch is from opensource (59681c331139e4d5424e77ff1614dc47fa8ddd8e, f5c4cd2f7f51f739f5f69eb4c857ccbfd8d51b0a)

    Summary:
    In case of RTL, the "custom" state properties does not apply. It happened because we don't copy the latest src to
    dst in set_state(PART:.., "custom", 0.0); in case of dst is already populated.
    We should copy the updated src to dst whenever we set the new custom description.

    @fix

    Reviewers: cedric, raster, jpeg, zmike, jaehwan

    Subscribers: kimcinoo, seoz, jpeg

    Differential Revision: https://phab.enlightenment.org/D339

Signed-off-by: Minwoo, Lee <minwoo47.lee@samsung.com>
Change-Id: Icf0b73f0cf2056e8f368c4215fc8139f2b4828e0