Reduce includes of platform specific files

This is done to avoid build issues in future.
For example previously the class "Duration" class caused build issues on
the MacOS platform due to a name conflict.

src/linux/advanced-scene-switcher-nix.cpp

@@ -14,7 +14,9 @@
 #undef Status
 #undef Unsorted
 #include <util/platform.h>
-#include "../headers/advanced-scene-switcher.hpp"
+#include <vector>
+#include <QStringList>
+#include <QRegularExpression>
 
 static Display *xdisplay = 0;