LibWeb: Rename painter() to recording_painter() in PaintContext

Using recording_painter() as a name is less misleading, indicating
the painter in stacking context traversal doesn't perform actual
painting commands.

Userland/Libraries/LibWeb/Painting/ButtonPaintable.cpp

@@ -59,7 +59,7 @@ void ButtonPaintable::paint(PaintContext& context, PaintPhase phase) const
         }
 
         // Paint button text clipped to button rect
-        auto& painter = context.painter();
+        auto& painter = context.recording_painter();
         painter.save();
         painter.add_clip_rect(button_rect.to_type<int>());
         painter.draw_text(