Terrain Designation ignore Buildings

Make terrain designation ignore all buildings so you can fill up terrain under a already construced building. The building will still collapse if the area under it is removed. This also fixed the problem with the not so clean Terrain filling next to retaining walls.

Just in console run command "toggle_terrain_designations_over_entities".
It is not on for safety reason, new player could definitelly destroy buildings when not carefull. But i agree, it should be an option in game, not only console command.