elementary: Fix elementary wayland border opaque region calculations
elementary: Fix elementary wayland border opaque region calculations

Summary: This fixes T2575 more accurately (combined with previous
theme adjustments). Previous code would use a spacer object to help
calculate window opaque region. This is no longer necessary due to the
previous theme changes, and now calculates window opaque region to
coincide with what Enlightenment is expecting.

@fix

Signed-off-by: Chris Michael <177aeddb9e34930a357ecd8dd2d21c80fe280c85@samsung.com>

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