Engine GUI: Don't translate mouse coordinates in GuiCanvas::setCursorPos()

Removed translating passed mouse pointer coordinates from client to screen space. Source comments and exposed canvas script API help doc line for the same function states that passed mouse pointer coordinates are supposed to already be in screen space.

Engine/source/gui/core/guiCanvas.cpp

@@ -549,8 +549,7 @@ void GuiCanvas::setCursorPos(const Point2I &pt)
    }
    else
    {
-      Point2I screenPt( mPlatformWindow->clientToScreen( pt ) );
-      mPlatformWindow->setCursorPosition( screenPt.x, screenPt.y ); 
+      mPlatformWindow->setCursorPosition(pt.x, pt.y);
    }
 }