Add Bobcat to shopkeeper for vehicle wreck cleanup

[thegamecracks]

Is your feature request related to a problem? Please describe.
Vehicle wrecks on the road can be a bit annoying for players to deal with, and in some cases may block bridges from being passed, at least by non-tracked vehicles.

Describe the solution you'd like
The shopkeeper should be able to sell a Bobcat for about 8000 BP which allows players to park next to vehicle wrecks and use a hold action to clear them.

Describe alternatives you've considered
Players could be able to clear wrecks themselves, making it much easier overall to deal with them.