Add missing qquaternion.h includes

The qquaternion.h include will vanish from qmatrix4x4.h soon, but some
TUs depended on on the transitive include.

This patch includes qquaternion.h into all TUs that use QQuaternion,
but didn't include its header.

I didn't check all the individual TU's history to make a detailed
"amends", so I'll just pick this all the way back, knowing there may
have been more users in older branches, or some TUs don't exist there,
but it since we're not picking the removal of qquaternion.h from
qmatrix4x4.h further than 6.10, I don't need to do detailed
checking. CI will tell me when something's wrong.

Pick-to: 6.5
Change-Id: Icf0db8ba4f12421fd46f9d1041f235bf4cc2c12b
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit bd1fa8379cf17db80228c89293ee5aa7152b3a35)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit bde0dd48e2c1354c9a6ba88b719109ad9e5656b0)
(cherry picked from commit d1c6073837e346606eff980572be14e7d85b0e8c)

examples/widgets/rhi/cuberhiwidget/examplewidget.cpp

@@ -3,8 +3,10 @@
 
 #include "examplewidget.h"
 #include "cube.h"
+
 #include <QFile>
 #include <QPainter>
+#include <QtGui/qquaternion.h>
 
 static const QSize CUBE_TEX_SIZE(512, 512);
 

tests/auto/gui/math3d/qmatrixnxn/tst_qmatrixnxn.cpp

@@ -3,7 +3,9 @@
 
 #include <QTest>
 #include <QtCore/qmath.h>
+
 #include <QtGui/qmatrix4x4.h>
+#include <QtGui/qquaternion.h>
 
 class tst_QMatrixNxN : public QObject
 {

tests/manual/rhi/rhiwidgetproto/examplewidget.cpp

@@ -3,8 +3,11 @@
 
 #include "examplewidget.h"
 #include "../shared/cube.h"
+
 #include <QFile>
+
 #include <QPainter>
+#include <QtGui/qquaternion.h>
 
 static const QSize CUBE_TEX_SIZE(512, 512);
 

tests/manual/stereographicsview/mygraphicsview.cpp

@@ -2,9 +2,12 @@
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
 
 #include "mygraphicsview.h"
+
 #include <QResizeEvent>
 #include <QFileDialog>
 
+#include <QtGui/qquaternion.h>
+
 Q_OPENGL_EXPORT QImage qt_gl_read_framebuffer(const QSize &size, bool alpha_format, bool include_alpha);
 
 MyGraphicsView::MyGraphicsView(QWidget *parent) :