Item groups don't spawn blacklisted items

[mqrause]

Summary

Bugfixes "Item groups don't spawn blacklisted items"

Purpose of change

In #79285 it came to light that blacklists weren't regarded with item group spawns.

Describe the solution

Add containers to item removal in item modifiers.
Also add containers to consistency check in item modifiers.
There's potential (and need honestly) for test cases here, but I want to see if it breaks existing tests before I work on that.

Describe alternatives you've considered

Testing

Ran tests with this PR on top of #79285 and [force_load_game] --mods=dda,generic_guns.

Additional context

[SurFlurer]

AFAIK item blacklist thing gets processed in void Item_factory::finalize_item_blacklist()? It tries to remove blacklisted items from every Item_spawn_data, which includes modifier ( container thingy ), Single_item_creator, and Item_group.

Maybe my reasoning for a9bcfa1 isn't as solid as I thought, and it broke the blacklist logic?

Update: No, generic guns still can prevent hwp modules from being spawned in item group robofac_gun_kit that includes an anonymous item group, so it should be ok.

[mqrause]

Oh, might actually be only modifiers are affected? I guess I do need to start with test cases after all.

[SurFlurer]

I can only find that the container_item of a Item_spawn_data doesn't get blacklisted. I can't test whether this is the problem, since I dunno the exact test case that blacklists fail to take effect.

[mqrause]

contents-item is what the mentioned PR tripped over. You can spawn the group ar15_22 with Generic Guns enabled to confirm.

[mqrause]

It appears to be a much simpler fix than initially anticipated, since the infrastructure for everything is already there, although I added another fix for another similar oversight.

Still need tests for this, though.