arch(driver): new driver architecture with new color format support

examples/widgets/dropdown/lv_example_dropdown_1.py

@@ -1,6 +1,6 @@
 def event_handler(e):
     code = e.get_code()
-    obj = e.get_target()
+    obj = e.get_target_obj()
     if code == lv.EVENT.VALUE_CHANGED:
         option = " "*10 # should be large enough to store the option
         obj.get_selected_str(option, len(option))
@@ -22,5 +22,5 @@ dd.set_options("\n".join([
     "Nuts"]))
 
 dd.align(lv.ALIGN.TOP_MID, 0, 20)
-dd.add_event_cb(event_handler, lv.EVENT.ALL, None)
+dd.add_event(event_handler, lv.EVENT.ALL, None)