Widgets/Fusion style: adjust painting of PE_Frame

Similar to the previous commits for QScrollBar and FrameTabWidget use
QPainter::Antialising and translate the painter by 0.5/0.5 to get a
proper result on high-dpi displays.

Fixes: QTBUG-126009
Pick-to: 6.11 6.10 6.8
Change-Id: Id0c1bc9e2720d6c51f5dd18bba4094ed985ed8a0
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

Author: chehrlic

src/widgets/styles/qfusionstyle.cpp

@@ -473,6 +473,8 @@ void QFusionStyle::drawPrimitive(PrimitiveElement elem,
             break;
         }
         QPainterStateGuard psg(painter);
+        painter->setRenderHint(QPainter::Antialiasing, true);
+        painter->translate(0.5, 0.5);
         painter->setPen(outline.lighter(108));
         painter->drawRect(option->rect.adjusted(0, 0, -1, -1));
         break;