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'?>
<BACnetServerNode xmlns:xsd="http://www.w3.org/2001/XMLSchema" UDP_Port_Number="47808" BACnet_Device_ID="3" BACnet_Communication_Control_Password=" " BACnet_Device_Location="Beremiz lab" Network_Interface="virbr0"/>