QQuickItemView: Fix max(X/Y)Extent()
QQuickFlickable maxXExtent() and maxYExtent() return the amount of space that is not shown when inside a ScrollView. QQuickItemView however just returned width() if vertical and height() if horizontal. In these cases just defer to the QQuickFlickable base implementation like minXExtent() and minYExtent() already do.
Fixes: QTBUG-83890 Pick-to: 6.2 6.4 Change-Id: I7f4060c2f46ae07611bedceca0d322c5f7f6affb Reviewed-by: Richard Moe Gustavsen richard.gustavsen@qt.io Reviewed-by: Shawn Rutledge shawn.rutledge@qt.io (cherry picked from commit 99047ae2)