Group Qt forward declarations separately from the others

src/base/utils/misc.h

@@ -37,6 +37,7 @@
 #endif
 
 class QString;
+
 enum class ShutdownDialogAction;
 
 /*  Miscellaneous functions that can be useful */

src/base/utils/string.h

@@ -33,6 +33,7 @@
 #include <QLatin1String>
 
 class QString;
+
 class TriStateBool;
 
 namespace Utils