Adding a welding store

[Milopetilo]

Summary

Content "Added a welding store"

Purpose of change

Closes #53685.
A quick googling shows that while not quite as common as normal hardware stores, welding stores are not too uncommon of a sight in NE. In order to account for this I have made them half as common as a single type of hardware store, meaning there is a ratio of ~1 welding store for every 8 hardware stores, which seems reasonable to me.

Describe the solution

Added a new welding store.

Describe alternatives you've considered

Make a variant of the hardware store which just happens to have a bit more welding supplies.

Testing

Game loads, building spawns, items & furniture spawn, terrain is correct, vehicles don't break things

Additional context

Screenshots c: