Add hotkey (F12) for switching perspective.

Switching perspective feature hides/restores all panels except of the main editor window for current FB.
So all available screen space is used for editor.

<?xml version='1.0' encoding='utf-8'?>
<BeremizRoot URI_location="LOCAL://">
  <TargetType/>
  <Libraries Enable_SVGUI_Library="false"/>
</BeremizRoot>