[Tab5] Lvgl Testing

[phillipsback]

Tab5 has a big screen. So I'm plan use it to learn lvgl on it.
But bad news is seems UIFlow2.0 using LVGL9, and rare data about that.

About issue of UIflow2.0:

1. While using widget with callback, in callback function use lv.get_target() seems can't get the object which fire event.
2. I am trying use slider, basicly function normal. Except leave finger out of screen after adjusting slider, slider holder will jump to position of 100%.