18NY - fix salvage rendering

[benjaminxscott]

addresses regression in #9136, adds tests

Please minimize the amount of changes to shared lib/engine code, if possible

If you are implementing a new game, please break up the changes into multiple PRs for ease of review.

Before clicking "Create"

• Branch is derived from the latest master
• [NA] Add the pins label if this change will break existing games
• Code passes linter with docker compose exec rack rubocop -a
• Tests pass cleanly with docker compose exec rack rake

Implementation Notes

• Explanation of Change

• Screenshots

• Any Assumptions / Hacks

[crericha]

I have a few issues with this PR:

1. The new fields are not tied into the game's salvaging logic. There should not be two sources of truth.
2. The button should change the verb based on which train is selected as there may be a mixture of salvageable and non-salvageable trains.
3. If we are going to have a common concept of salvage, it should be supported in common code and not game specific code.

I personally don't think this reported issue needs to be fixed, but won't oppose a fix if done properly and completely.

[benjaminxscott]

@crericha - I don't disagree, will send a slack DM

[benjaminxscott]

Will work on generalizing later on