Fix redraw problems in preview frames and debug panel

The problem was that direct call of RefreshView (now DrawView) doesn't
generate EVT_PAINT (at least on GNU/Linux with Wayland and wxgtk build
with gtk3+ support).
Now RefreshView simply triggers EVT_PAINT and EVT_PAINT handler does actual work.

<?xml version='1.0' encoding='utf-8'?>
<BaseParams xmlns:xsd="http://www.w3.org/2001/XMLSchema" IEC_Channel="0" Name="py_ext_0"/>