[V9] request widget mask like lv_objmask or mask example

In v9 we focused on better GPU support so we have dropped the “home-made” masking solutions.

The current solution is to support masking with a bitmap. LVGL’s rendering features are being extended to allow drawing in L8, A8, and AL88 formats. See here.

This way you will be able to generate masks at run time using an lv_canvas.