Meson: Make spacing and #include ordering a bit more consistent

Not 100%, but a step forward.

Change-Id: I6957edbd24c1652b228a96a68424b857603aae45
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/mesonprojectmanager/tests/testmesonwrapper.cpp

@@ -24,13 +24,15 @@
 ****************************************************************************/
 
 #include "exewrappers/mesonwrapper.h"
-#include <iostream>
+
 #include <QDir>
 #include <QObject>
 #include <QString>
 #include <QTemporaryDir>
 #include <QtTest/QtTest>
 
+#include <iostream>
+
 using namespace MesonProjectManager::Internal;
 
 namespace {