• Add render_aa and viewport_aa sampling setting for workbench. 0 samples means no AA, 1 sample uses FXAA and more samples will use TAA. The viewport gpu_viewport_quality can still limit viewport anti-aliasing method.
• Use TAA when rendering images. (this used to be CPU based FSAA)
• Removed R_OSA related settings.

Fix: T60847

When using the view3d -> View -> Viewport Render Animation, Viewport Render Image it now renders quick, but only with a single sample for EEVEE and no AA for workbench. This is because it starts a offscreen render, an offscreen render calls viewport drawing stuff.

When doing Render -> Render Animation, Render Image the draw manager will trigger the render_image of EEVEE and Workbench that does iterate over the samples.

Design question: Is should we connect the offscreen rendering to the image_render part of the draw engines, so it will use the correct settings?

Side note: R_FULL_SAMPLE and V3D_OFSDRAW_USE_FULL_SAMPLE are currently unused and could be removed also. If so, would create a different patch for this as it is not directly related to viewport anti aliasing.