chore(libs/png): rename lv_png to lv_lodepng (#4574)

Signed-off-by: pengyiqiang <pengyiqiang@xiaomi.com>
Co-authored-by: pengyiqiang <pengyiqiang@xiaomi.com>

examples/libs/lodepng/lv_example_lodepng_1.py

@@ -0,0 +1,32 @@
+#!/opt/bin/lv_micropython -i
+import lvgl as lv
+import display_driver
+from img_wink_png import img_wink_png_map
+
+image_wink_png = lv.image_dsc_t(
+    {
+        "header": {"always_zero": 0, "w": 50, "h": 50,  "cf": lv.COLOR_FORMAT.RAW_ALPHA},
+        "data_size": 5158,
+        "data": img_wink_png_map,
+    }
+)
+image1 = lv.image(lv.scr_act())
+image1.set_src(image_wink_png)
+image1.align(lv.ALIGN.RIGHT_MID, -250, 0)
+
+# Create an image from the png file
+try:
+    with open('wink.png','rb') as f:
+        png_data = f.read()
+except:
+    print("Could not find wink.png")
+    sys.exit()
+
+wink_argb = lv.image_dsc_t({
+  'data_size': len(png_data),
+  'data': png_data
+})
+
+image2 = lv.image(lv.scr_act())
+image2.set_src(wink_argb)
+image2.align(lv.ALIGN.RIGHT_MID, -150, 0)