moving non critical settings to sd

based on WillyJL's work

TODO: fix loader_menu

applications/services/desktop/desktop_settings.h

@@ -9,6 +9,10 @@
 #define DISPLAY_BATTERY_RETRO_5          4
 #define DISPLAY_BATTERY_BAR_PERCENT      5
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef enum {
     FavoriteAppLeftShort,
     FavoriteAppLeftLong,
@@ -49,3 +53,7 @@ typedef struct {
 
 void desktop_settings_load(DesktopSettings* settings);
 void desktop_settings_save(const DesktopSettings* settings);
+
+#ifdef __cplusplus
+}
+#endif