refactor(API): don't expose private symbols in lvgl.h. phase-out "_lv*" names (#6068)

Co-authored-by: Gabor Kiss-Vamosi <kisvegabor@gmail.com>

src/draw/vg_lite/lv_vg_lite_decoder.c

@@ -7,6 +7,7 @@
  *      INCLUDES
  *********************/
 
+#include "../lv_image_decoder_private.h"
 #include "lv_vg_lite_decoder.h"
 
 #if LV_USE_DRAW_VG_LITE
@@ -14,6 +15,7 @@
 #include "lv_vg_lite_utils.h"
 #include <stdlib.h>
 #include <string.h>
+#include "../../core/lv_global.h"
 
 /*********************
  *      DEFINES