Migration to v9.1 lv_draw_mask_add

I try to migrate the lv_meter widget, because i use it a lot and it is a good learning exercise.
Most items I can resolve but lv_draw_mask_add seems to be removed in v9.1 but there is no information I can find on a replacement or if it is not needed any more.

What LVGL version are you using?

v8.3 ==> v9.1

What do you want to achieve?

port lv_meter

The code block(s) should be formatted like:

		lv_draw_sw_mask_radius_init(&outer_mask, &area_outer, LV_RADIUS_CIRCLE, false);
		int16_t outer_mask_id = lv_draw_mask_add(&outer_mask, NULL);

Screenshot and/or video

If possible, add screenshots and/or videos about the current state.