twp-step: Remove superflous is_hidden / is_stopped checks from on_draw

twp-step: Remove superflous is_hidden / is_stopped checks from on_draw

Remove superflous is_hidden / is_stopped checks from our on_draw
handler. In all 3 cases the is_hidden / is_stopped check guards
a draw_area call, but the draw_area calls themselves contain the
same check, so it checking this in on_draw is not necessary.

Also note that we are already not doing such a check for e.g. the
progress_bar so lets be consistent and remove the check everywhere.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>