Refactor: Remove train_actions_always_use_operating_round_view

[ventusignis]

In assets/app/view/game_page.rb there is a somewhat hacky conditional for 1840 that can be cleaned up to be cleaner. This is currently known to affect 1840 and 18USA.

oh crap :D
in 1840 the merger round is the "buy tram lines". There is a "real" buy and a scrap train step in it.

I am not sure how to resolve that other than chris suggested. I need a real view and chris does not need a real view, just the action.
Maybe the name could be clearer, or we could add a "show_action_view?" to the step. This would put the logic more into the steps and away from the game.

Did that somehow help? ;)

Originally posted by @Zwergenpunk in #7099 (comment)