Compositor: Move Execution Mode and Precision from bNodeTree to Scene

This allows to expose these settings in the Performance panel in the
render buttons. Also moves compositor-specific options away from the
generic node tree structure.

For the backwards-compatibility the options are still present in the
DNA for the bNodeTree. This is to minimize the impact on the Studio
which has used the GPU compositor for a while now. They can be
removed in a future release.

There is no functional changes expected.

Pull Request: https://projects.blender.org/blender/blender/pulls/121583

scripts/startup/bl_ui/space_node.py

@@ -823,19 +823,19 @@ class NODE_PT_quality(bpy.types.Panel):
         layout.use_property_split = True
         layout.use_property_decorate = False
 
+        scene = context.scene
+        rd = scene.render
+
         snode = context.space_data
         tree = snode.node_tree
         prefs = bpy.context.preferences
 
-        use_realtime = False
         col = layout.column()
         if prefs.experimental.use_experimental_compositors:
-            col.prop(tree, "execution_mode")
-            use_realtime = tree.execution_mode == 'REALTIME'
-        col.prop(tree, "precision")
+            col.prop(rd, "compositor_device", text="Device")
+        col.prop(rd, "compositor_precision", text="Precision")
 
         col = layout.column()
-        col.active = not use_realtime
         col.prop(tree, "use_viewer_border")
 
         col = layout.column()