Move fileutil, net, image loaders, ui to Common. (#13506)

* Move and rename file_util/fd_util to Common/File/FileUtil and DirListing

Let's also move net while we're at it.

Move the ZIM/PNG loaders over to Common.

Move the UI framework into Common

iOS buildfix

* Buildfix

* Buildfixes

* Apple buildfix

* This typo again..

* UWP buildfix

* Fix build of PPSSPPQt, such as it is (it's not in good condition...)

* Guess what? Another buildfix.

UI/ProfilerDraw.cpp

@@ -19,8 +19,8 @@
 #include <inttypes.h>
 
 #include "gfx_es2/draw_buffer.h"
-#include "ui/ui_context.h"
-#include "ui/view.h"
+#include "Common/UI/Context.h"
+#include "Common/UI/View.h"
 #include "Common/Profiler/Profiler.h"
 
 static const uint32_t nice_colors[] = {