Split utilities functions into separate files

src/context/contextalbum.cpp

@@ -37,7 +37,7 @@
 #include <QContextMenuEvent>
 #include <QPaintEvent>
 
-#include "core/imageutils.h"
+#include "utilities/imageutils.h"
 #include "covermanager/albumcoverchoicecontroller.h"
 
 #include "contextview.h"

src/context/contextview.cpp

@@ -51,8 +51,9 @@
 #include "core/application.h"
 #include "core/player.h"
 #include "core/song.h"
-#include "core/utilities.h"
 #include "core/iconloader.h"
+#include "utilities/strutils.h"
+#include "utilities/timeutils.h"
 #include "widgets/resizabletextedit.h"
 #include "engine/engine_fwd.h"
 #include "engine/enginebase.h"