ivi-shell: Automatically schedule view repaints on property changes

This is my attempt at completing !1313 (merged) for ivi-shell.

Use weston_view_add_transform(), weston_view_set_alpha() an weston_view_move_to_layer() instead of partially open-coding them.

This removes a tiny amount of manual list manipulation and stops calling weston_view_schedule_repaint(), which now happens implicitly.

Based on !1313 (merged).