Stop deferring view transform updates

As discussed on !1053 (merged), deferring these transform updates causes us some discomfort.

As mentioned at !1053 (comment 1632462) the goal is to remove the dirty flag entirely and minimize the weston_view_update_transform() call sites.

The exact reason for these deferrals is not well remembered - perhaps performance due to the fact that a surface can be moved many times between renders. The transform update process performs maths for each of these moves, but also tracks damage. This problem maybe be improved or resolved by #494