BaseTheme is no more 🦀 (#4132)

Co-authored-by: pajlada <rasmus.karlsson@pajlada.com>

src/widgets/BaseWidget.cpp

@@ -1,9 +1,9 @@
 #include "widgets/BaseWidget.hpp"
 
 #include "BaseSettings.hpp"
-#include "BaseTheme.hpp"
 #include "common/QLogging.hpp"
 #include "controllers/hotkeys/HotkeyController.hpp"
+#include "singletons/Theme.hpp"
 #include "widgets/BaseWindow.hpp"
 
 #include <QChildEvent>