Move viewport render state mapping to renderer gl

docs/modernization/roadmap.md

@@ -433,6 +433,9 @@ delegate to `pp_renderer_gl`; `Font` no longer spells GL enum names directly.
 Canvas undo/redo dirty-region texture updates and readbacks now also delegate
 their 2D texture target, RGBA pixel format, and unsigned-byte component type
 mapping to `pp_renderer_gl`.
+`NodeViewport` preview rendering now also delegates viewport query,
+clear-color query, color-buffer clear mask, and blend-state tokens to
+`pp_renderer_gl`.
 The existing renderer classes are not yet fully
 behind the renderer interfaces.