offscreen-effect: Update handling of transforms
offscreen-effect: Update handling of transforms

In line with the changes made in f5f066df9ce7 to clean up how Clutter
deals with transformations of actors this patch updates the code in
clutter-offscreen-effect.c. We now query the projection matrix from the
stage instead of the perspective and instead of duplicating the logic to
setup the stage view transform we now use
_clutter_actor_apply_modelview_transform for the stage instead.

GNOME/clutter,spatulasnout/clutter,Distrotech/clutter,nobled/clutter,Distrotech/clutter,dlespiau/clutter,jigpu/clutter,ebassi/clutter,kerrickstaley/clutter-vala,jigpu/clutter,heysion/clutter-clone,djdeath/clutter-android,collects/clutter,kerrickstaley/clutter-vala,nobled/clutter,Distrotech/clutter,ebassi/clutter,ebassi/clutter,collects/clutter,dlespiau/clutter,GNOME/clutter,jigpu/clutter,kerrickstaley/clutter-vala,djdeath/clutter-android,ebassi/clutter,ebassi/clutter,spatulasnout/clutter,jigpu/clutter,djdeath/clutter-android,djdeath/clutter,djdeath/clutter-android,spatulasnout/clutter,djdeath/clutter-multithreaded,djdeath/clutter,heysion/clutter-clone,kerrickstaley/clutter-vala,Distrotech/clutter,djdeath/clutter-multithreaded,dlespiau/clutter,Distrotech/clutter,spatulasnout/clutter,djdeath/clutter-android,collects/clutter,collects/clutter,djdeath/clutter,djdeath/clutter,spatulasnout/clutter,djdeath/clutter,heysion/clutter-clone,GNOME/clutter,djdeath/clutter-multithreaded,Distrotech/clutter,nobled/clutter,djdeath/clutter-multithreaded,djdeath/clutter,collects/clutter,GNOME/clutter,heysion/clutter-clone,jigpu/clutter,GNOME/clutter,heysion/clutter-clone,jigpu/clutter