Initial custom asset pack support

applications/settings/xtreme_settings/xtreme_assets.h

@@ -1,7 +1,10 @@
 #pragma once
 
+#include <gui/icon_i.h>
 #include "xtreme_settings.h"
-#include "assets_icons.h"
+#include <toolbox/path.h>
+
+#define PACKS_DIR EXT_PATH("dolphin_custom")
 
 typedef struct {
     const Icon* passport_happy;
@@ -12,3 +15,7 @@ typedef struct {
 XtremeAssets* XTREME_ASSETS();
 
 void XTREME_ASSETS_UPDATE();
+
+void swap_bmx_icon(const Icon** replace, const char* base, const char* name, FuriString* path, File* file, int i);
+
+void free_bmx_icon(Icon* icon);