Include qproperty.h where needed

Don't rely on transitive include from qobject.h, which will go away.

Change-Id: I99dd97ff4fb1d0632d040daab0bffa2d7b85d3ae
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

src/testlib/qpropertytesthelper_p.h

@@ -52,6 +52,7 @@
 //
 
 #include <QtCore/QObject>
+#include <QtCore/QProperty>
 #include <QtTest/QSignalSpy>
 #include <QTest>
 

tests/auto/corelib/animation/qsequentialanimationgroup/tst_qsequentialanimationgroup.cpp

@@ -28,6 +28,7 @@
 
 #include <QTest>
 #include <QVariantAnimation>
+#include <QProperty>
 #include <QPropertyAnimation>
 #include <QSignalSpy>
 #include <QParallelAnimationGroup>

tests/auto/corelib/kernel/qobject/tst_qobject.cpp

@@ -40,6 +40,7 @@
 
 #include <qcoreapplication.h>
 #include <qpointer.h>
+#include <qproperty.h>
 #include <qtimer.h>
 #include <qregularexpression.h>
 #include <qmetaobject.h>

tests/auto/corelib/kernel/qtimer/tst_qtimer.cpp

@@ -40,6 +40,7 @@
 #include <qtimer.h>
 #include <qthread.h>
 #include <qelapsedtimer.h>
+#include <qproperty.h>
 
 #if defined Q_OS_UNIX
 #include <unistd.h>

tests/auto/gui/image/qmovie/tst_qmovie.cpp

@@ -36,6 +36,7 @@
 #include <QLabel>
 #endif
 #include <QMovie>
+#include <QProperty>
 
 class tst_QMovie : public QObject
 {