Allow highlighting obstacles in the line of fire for ammo categories other than "railgun"

[Teppy381]

I was looking at the cannon turret mods and how these turrets destroy walls in front of them. Just like railguns!
I've spend a day searching why railgun turrets highlight obstacles and it seems that it works only with ammo_category = "railgun". That's unfortunate since ammo_category = "railgun" implies some heavy limitations and I don't see a way to make a cannon turret with that.

example.jpg (526.86 KiB) Viewed 234 times

I think it would be nice to have a way to show obstacles to the player since railguns already do this.