When printing, pads are not always printed (especially on tech layers)

A printing mode is added, to force ViewGetLOD() to return 0 in printing mode (pads are always drawn)

Fixes: lp:1809528
https://bugs.launchpad.net/kicad/+bug/1809528

common/view/view.cpp

@@ -303,6 +303,7 @@ VIEW::VIEW( bool aIsDynamic ) :
     double size = coord_limits::max() - coord_limits::epsilon();
     m_boundary.SetOrigin( pos, pos );
     m_boundary.SetSize( size, size );
+    SetPrintMode( 0 );
 
     m_allItems.reset( new std::vector<VIEW_ITEM*> );
     m_allItems->reserve( 32768 );