Don't remove tracks when demolishing a station module

Right now when you demolish a station module the tracks that were part of it are removed too, even when the module was built next to tracks that already existed. This is frustrating to play with also unintuitive.

If that was changed others could be irritated with having to demolish tracks after. Also not good with mass deconstruction of area.

Could be done with having module "train tracks" and force rebuilding with that (it will change to tracks after that). Or with force build by rails directly.

That's a good point. Being able to force build plain train tracks over the top works.

Ultimately the issue is that modules don't exist alongside tracks, they are the tracks. But I'm guessing that's not a small change.