In recent changes the viewport_quality setting was not working what
users expected. This change will separate the anti-aliasing method that
is being used.
We now have three settings:
* scene.display.render_aa: Will be used during `Render Image`.
* scene.display.viewport_aa: Will be used during `Viewport Render Image`.
* userpref.viewport_aa: Will be used in the 3d view.
The viewport_quality setting has been replaced by the viewport_aa
setting as it was the only thing in currently controlled.
Reviewed By: brecht
Maniphest Tasks: T64132
Differential Revision: https://developer.blender.org/D4828
0764cfe3de